The vertical battlefield.

"The worst policy is to attack cities ... attack cities only when there is no alternative." wrote Sun Tzu in his Art of War (c. 500 BC). He was correct: urban fighting involves challenges and costs that can far exceed those of conventional warfare. The effectiveness of superior weapons and communications technology is blunted in the urban environment, but new tactics, training and equipment are being developed to try to overcome these disadvantages.

Armies fight in cities not because they want to, but because they have to. Population, especially in the developing world, is rising rapidly and becoming more city-centric. One estimate suggests that by the year 2010 75 percent of the world's population will live in urban areas. American military doctrine recognises that cities are the battlefields of the future, but urban warfare presents special challenges, especially for the attacker.

The Problems

The problems are greatest for technologically advanced attackers who face determined defenders. Classic recent and current examples are the Russians in Grozny, Israelis in the towns of the Gaza Strip and West Bank and American forces in Iraq and Afghanistan. Urban fighting sharply reduces the effectiveness of sophisticated sensors and weaponry and favours less sophisticated mobile weaponry, local knowledge and guerrilla tactics.

Cities have two defining features that make urban warfare difficult: buildings and people.

Imagine a battlefield that has been folded back on itself multiple times, so that a conflict which would cover a much wider area on level ground is compressed into a few square kilometres. This is the urban battlefield, vertical rather than horizontal, a '360-degree fight' in which upper floors of buildings, basements, sewers and tunnels are all places where defenders can hide from and fire on attackers in the streets.

This compressed and complex battlefield makes it difficult for commanders and troops to gain an overview of the action, while the small area of action increases the likelihood of fratricide. The urban landscape offers increased possibilities for ambushes and flanking operations: buildings, and even the rubble from buildings, provide cover for snipers and mobile artillery such as RPGs (rocket-propelled grenade launchers).

Also, a tank that breaks down can block an entire line of advance, a fact that the Chechen defenders used to their advantage in the 1994-95 battle for Grozny. Confident in their superior firepower, the Russians paraded through the streets in columns converging on the presidential palace. By disabling the tanks at the front and rear of each column, the Chechens immobilised the rest and were able to attack them at leisure.

Conventional air strikes are of limited effectiveness in cities, partly because of the greater risks of collateral damage and partly because of terrain features. Urban canyons reduce the ability of aircraft to manoeuvre, and so make them more vulnerable to attack by air defence artillery and missiles hidden on high buildings. The combination of high-rise buildings and low cloud further reduces the effective above ground level (AGL) operating area, while aircraft silhouetted against overcast skies are easy targets. The 'clutter' of lights, smoke and dust can obscure ground fire or missile launches and create visual confusion.

Tanks, artillery and missile batteries are at a similar disadvantage, designed for firing at targets at a distance and on the flat. Closely packed buildings deny conventional weapons adequate range and lines of sight, while limits on gun elevation and depression create areas that are safe from fire--for instance in basements and in tall buildings.

Other disadvantages are subtler. Night vision goggles and thermal sights may be dazzled by city lights, fires and background illumination. Reduction in visibility can similarly degrade the performance of weapons sensors and laser- or optically-guided weapons. Turbulence caused by wind channelled along city streets can affect aircraft performance and weapons delivery. Smooth urban surfaces increase the chance of ordnance ricocheting or 'rabbiting', while impact-fused explosive rounds may not detonate at all if fired against rubble. Fighting in close quarters means that fragments from the exploding target as well as muzzle blast and back blast can cause injury to those firing the weapon.

Navigation and communication capabilities are also fragmented by the city landscape. High buildings block radio communication and GPS satellite navigation. Available military maps are often inadequate and out-of-date, especially once landmark buildings are reduced to piles of rubble. Important battle areas below ground and inside buildings are not visible to reconnaissance planes or drones, and stealthy movement is difficult in a strange environment.

People--the attackers, defenders, civilian population and other groups such as the media--further complicate the urban warfare picture. One problem the urban commander faces is situational awareness, or knowing where all these people are. With communication links faulty and reporting difficult, basic questions such as; Where am I? Where are my soldiers? Where are friendlies? Where is the enemy? may be difficult to answer with any certainty.

The small combat units that are typical of urban warfare are even more isolated, physically and in terms of communications, both from their commander and from other units in the same area. Fighting at close quarters is stressful and increases the chances of fratricide and breakdowns in discipline.

In urban warfare, the defenders can be difficult to distinguish from the civilian population, while relations with the city's inhabitants can be as complex as the terrain. General Charles Krulak, the former Commandant of the United States Marine Corps, described future urban operations as a 'three block war', suggesting that the attackers may be providing humanitarian assistance in one part of the city, conducting peacekeeping operations in another and fighting a lethal mid-intensity battle in a third part.

CNN Syndrome

There is a fourth 'block': the media. By denying access to foreign journalists, the Israeli Defence Force left the Palestinians to tell the only available stories of the April 2002 attack on Jenin in occupied territories of the West Bank, and widespread media reports of a massacre resulted. In January 2003, a conference report by the Jaffee Centre for Strategic Studies at Tel Aviv University concluded that greater openness would be essential in future Israeli combat operations. But media access creates its own problems. Ever since the battle for the city of Hue during the Vietnam War, commanders have had to reckon with the impact of their operations on home viewers watching the evening news.

US Army doctrine recognises the urban warfare threat to non-combatants and recommends removing them from the scene. But this can be easier said than done. The Israeli forces attempted to evacuate Jenin before beginning action against Palestinian Islamic Jihad forces there, but approximately 2000 of the 13,000 inhabitants of the camp chose to stay behind. In the days before the November 2004 assault on Fallujah, the offer of free passage to non-combatants allowed hundreds of insurgents, including their leader Abu Musab Zarqawi, to escape.

The Cost Factor

Urban warfare requires more of almost everything than conventional warfare does, and casualties are historically higher. In 2003 US Army doctrine assumed three to six times greater casualty rates than in any other environment, although in recent engagements such as Fallujah the initial toll was lighter than expected.

Casualties come not just from weapons but also from shattered glass, falling debris, rubble, ricochets, fires and falls from heights. Stress, illness and environmental hazards such as contaminated water and toxic industrial materials increase the numbers. Even without casualties, more troops are needed to attack a city than to defend it. A proportion of these will need to stay back to secure captured buildings and keep access routes clear, reducing the numbers available for the advance.

In the wake of the Grozny campaign, some analysts, both Western and Russian, argued that the costs of urban warfare were too high and recommended standoff tactics, in effect a modern siege instead. But most accept that fighting in cities is a necessary evil. If this is so, what are the factors that can help make urban warfare more effective?

Possible Solutions

What is profoundly different about urban warfare is the terrain. Thinking, tactics, training and technology all need to adapt to a very different situation.

Until recently military thinking was dominated by the 'total war' model of World War II, in which civilian deaths and the destruction caused by heavy bombing were acceptable. One of the differences in modern urban warfare is that avoiding collateral damage has become a major declared objective. This radically changes military rules of engagement.

Tactics

Serious military thinking about the problems of modern urban warfare is relatively new. The 1976 edition of US Army field manual FM 100-5, Operations, admitted, <<The whole subject of combat in built up areas is one in which the US Army is not well versed.>> This is changing, and the result is tactical thinking which takes into account the special circumstances of three-dimensional warfare.

Two important areas of tactical thinking concern the roles of tanks and aircraft, especially attack helicopters, in modern urban warfare. The lessons of Grozny and the 'BlackHawk Down' scenes in Mogadishu suggest that both platforms are vulnerable in urban operations, but their advocates say that a change in tactics, in particular their use in combined operations, can make both an effective tool.

A 2001 monograph by Major Frank Tate of the School of Advanced Military Studies, United States Army Command and General Staff College, Fort Leavenworth, Kansas, argues that 'attack helicopters have the flexibility, precision, firepower and responsiveness that ground combat forces desperately need to move through a hostile city.' Somewhat surprisingly, he points to Russian air attacks on Grozny to support this claim. The Russians used precision-guided weapons at close range, flying only over buildings and terrain that were controlled by Russian ground soldiers. Attacks were co-ordinated by Russian forward air controllers on the ground.

Tate concluded that aircraft survival in the city is significantly increased when they operate over terrain held by friendly forces. He also points to the importance of developing new training and tactics, focusing on running and diving fire at close range and combined arms training with infantry.

Working together in an urban environment, infantry and armour can form mutually supporting teams that complement each other's strengths and mitigate each other's weaknesses. Unsupported armour is vulnerable to anti-tank teams with weapons such as RPGs. Unsupported infantry is vulnerable in open spaces, but can move through buildings to clear enemies from an area and provide security for the tank advance, protecting the vulnerable flanks and rear of armoured vehicles. Tanks in turn provide suppressive fire to protect the infantry. Further support can be provided by engineers and artillery, as well as aircraft and drones, to create a total force capable of fighting in three dimensions.

Communications between members of a team and with other teams is probably more important, and more feasible, than communicating with headquarters. As Marshal Vasili I. Chuikov, Hero of the Soviet Union and Defender of Stalingrad, once observed, 'In street fighting, a soldier is on occasion his own general'.

In some cases, the technologies for achieving such low-level communications are low technology. Tanks and infantry should be marked in an easily seen way so they can identify one another, and buildings should be marked to indicate capture by friendly forces. Soldiers can carry a simple 'cheat card' containing a small map identifying objectives and the call sign and radio frequency of each company operating in the area.

Training

Tactics need to be communicated to those who are doing the fighting. One way of doing this is through training. As with doctrine, training in the techniques of urban warfare is relatively new, as the US Marines started urban training programmes in the 1980s, the US Army about a decade later.

Currently both forces use large and sophisticated LVC (live, virtual, constructive) training programmes. These involve a network to co-ordinate live action, vehicle simulators and computer war games. Replica Iraqi villages are springing up at US Army training facilities all over the United States. 'Leschi Town'--originally built at Fort Lewis, Washington to train tank crews in mock battles against a Russian enemy makes it the world's most complete urban training facility. Urban training is also being upgraded and expanded at the US Army's National Training Center at Fort Irwin, California, and the JRTC (Joint Readiness Training Center) at Fort Polk, Louisiana. In all, some 80 new facilities have been funded for construction through 2009. The aim is to expose trainees to the sights, sounds and feel of combat operations, and also to the cultural differences they will encounter in Iraq. Fort Polk employs up to 1000 actors, including some 200 Arabic speakers playing combatants and civilians in 18 villages spread over 40,000 acres.

More training in close-action firing, using new weapons and sights being developed for the Iraq war, is also being emphasised by US Marine and Army training teams. At Camp Lejeunc, North Carolina, Marines develop combat shooting techniques and accuracy at short distances through the Enhanced Marksmanship Program (EMP). A two-day Weapons Manipulation Live Fire course run by the I Marine Expeditionary Force's Special Operations Training Group at Camp Pendleton, California, is also teaching close-in combat and firing skills. The transportation school at Fort Eustis, Virginia, is developing weapons training for drivers, using live rounds and simulated weapon systems, performed in a mock city to simulate urban conditions.

Computer-based training also sharpens urban warfare skills. Urban Resolve is a major distributed computer simulation created by US Joint Forces Command's J9 Joint Experimentation Directorate and Joint Futures Laboratory. It allows rival teams in three locations to develop tactics for attack and defence in a 'virtual' city of 2015. The simulation makes heavy use of C4ISR (command, control, communications, computers, intelligence, surveillance and reconnaissance) systems.

Even the multi-role computer game played on personal computers has been pressed into service as a training aid intended to train units going to Iraq on better ways to avoid being ambushed. The experience of 'dying' several times in succession teaches lessons that the US Department of Defense hopes will stick in the soldier's mind.

Portable simulations that can be used by troops in theatre are also an urgent requirement. One problem faced by raiding parties searching for insurgents or hidden weapons is that they have probably never been to the house they are about to raid and may not even have been to the immediate neighbourhood. Even if a good GPS signal can be obtained, the soldiers run the risk of breaking into the wrong building. At best, this might give the target time to escape; at worst it might provide impetus for some irate new recruits to go over to the insurgency side. Darpa's Urbanscape programme is working on the technologies needed to create three-dimensional images of the actual neighbourhood and the specific building that has been targeted.

Technology

Intelligence gathering, small arms and sniper equipment, specialised weapons, improved armoured fighting vehicles and other weapons are some of the major technologies that have emerged from urban warfare requirements.

One major problem in urban warfare is mapping complex three-dimensional terrain in a way that provides clear and usable information for those moving through it. Such is the speed with which towns and cities evolve that traditional maps with be out of date. Even if they are not, maps will not show the internal structure of specific buildings, or underground features such as sewers that could be exploited by either side. Intelligence officers must be equipped and trained to handle the task of dynamically mapping buildings and other locations of interest. Noting the location of doors and windows may not be enough; they need to be able to locate internal shafts and ducts, and even combat-relevant features of the electrical wiring and water system.

Most of today's hardware used for intelligence gathering (such as overhead reconnaissance and electronic intelligence-gathering systems) was designed to meet the needs of open terrain warfare, but is much less effective when tasked with tracking down mobile or even irregular forces within a city. "Our current surveillance and reconnaissance systems simply cannot provide enough information of the type needed to understand what's really going on throughout a city", Darpa Director Dr. Tony Tether told the US Senate Committee On Armed Services' Subcommittee On Emerging Threats And Capabilities, in March, 2005. <<Persistent, staring reconnaissance, surveillance and target acquisition systems would vastly improve knowledge about what's going on throughout a city in all three dimensions and over time,>> he told the Subcommittee.

"We need a network, or web, of sensors to better map a city and the activities in it, including inside buildings, to sort adversaries and their equipment from civilians and their equipment, including in crowds and to spot snipers, suicide bombers or improvised explosive devices. We need to watch a great variety of things, activities and people over a wide area and have great resolution available when we need it. And this is not just a matter of more and better sensors, but just as important, the systems needed to make actionable intelligence out of all the data."

Imagery NOW!

The imagery from drones can play a major role in locating targets, but only if their imagery is immediately available to the front-line units taking part in combat operations. Traditional drone operating techniques involve the air vehicle being controlled from a rear position and sending its information to that position. For urban warfare, the units engaged in combat need to be able to task drones and directly obtain the data they need.

Working under an $11.6 million Darpa contract, Northrop Grumman is developing a heterogeneous urban reconnaissance, surveillance and target acquisition (Hurt) technique that would allow soldiers to ask for reconnaissance imagery unobtainable by high-altitude or fixed sensors. The Hurt is intended to simultaneously order drones to conduct wide-area surveillance while dispatching an individual air vehicle to any location that is requested by a soldier to provide a close-up look.

Israeli experience in using tactical drones to support operations in Palestinian Authority-controlled territory has highlighted a need for lightweight systems that can be operated autonomously by front-line units. When packed into its launcher/container, the electrically powered Rafael Skylite is small and light enough to allow one soldier able to carry two air vehicles in a backpack, while another carries the ground control station. The plane is 1.1 metres long, has a wingspan of 1.7 metres and weighs 6.5 kg. After launch it can fly a fully autonomous mission using pre-programmed waypoints. After being recovered using a ground net, the vehicle can be fitted with a fresh battery and booster then folded and repacked into the launcher/container.

The Israel Aircraft Industries (IAI) Mosquito is even smaller. An electrically-powered drone intended to monitor a local area up to one km x one km after being launched by hand or bungee, it is only 34 cm in wingspan and 30 cm long. It weighs 500 grams at launch and can fly at heights of up to 300 ft. Drones in this miniature category are small enough to be flown through a window to obtain images of a building's interior.

Bertin in France started developing the vertical take-off and landing HoverEye in 1999. It was recently demonstrated to the French procurement authorities (DGA) and is now ready for marketing through Sagem. Partnership with Sagem involves integration work, particularly with the French Felin and Boa programmes in sight. Electrically powered, the HoverEye incorporates an obstacle avoidance radar, uses inertial navigation and GPS, but to remedy the inefficiency of the latter in urban environment, Bertin is currently working on a visual recognition back-up system. Weighing 3 to 3.5 kilos, the electrically powered, carbon-glass fibre composite HoverEye has an autonomy of about 15 minutes, however, a thermal engine is also envisaged as an option for increased endurance.

PackBots, the briefcase-sized robots with cameras that became stars of the TV news, made their debut in Afghanistan and have since been deployed in Iraq, moving through buildings to track insurgents.

The Centre for Emerging Threats and Opportunities' Reconnaissance Surveillance and Target Acquisition Cloud concept has explored the use of small or even micro-sized robots for reconnaissance, a potentially useful tool in Third World urban environments where Western military personnel would be highly conspicuous among the civil population.

On a digitised urban battlefield, ground-based fixed or mobile sensors could be linked to armed drones, allowing fire to be delivered against mobile targets at short notice. However, engineers face the problem of making such sensors small enough to be unnoticeable by the local populace.

In some cases, sensors are designed to be fired or even hand-thrown. Titan's Grenade-Launched Imaging Modular Projectile System (Glimps), combines a camera and a radio transmitter in a 40mm projectile. Currently under development, it is intended to extend surveillance capabilities in an urban environment.

Rafael is developing a similar product, but the prime role of its Firefly is to capture imagery of the terrain being over-flown. Fired from a 40 mm grenade launcher it has a maximum range of 600 metres. Combat evaluation by the Israel Defense Force is expected later this year. Another product with a similar role is the Israel Military Industries surveillance variant of its rifle-launched Air Burst Ammunition (ABA). While the basic ABA is a munition that can be fired in airburst, point detonation and time-delayed detonation modes, the surveillance version carries a digital camera and wireless datalink.

Although there is no shortage of new sensors, their imagery still needs to be rapidly interpreted to provide useable intelligence. Sensors that can sort civilians from suicide bombers are unfortunately not yet available, although USDigiComm has, in the process of designing a short-range concealed weapon detector for indoor use, developed a long-range detector that can recognise handguns and bombs outside and at a safe-enough distance to protect both personnel and assets. There are no known weapon detection systems on the market today that can detect concealed weapons from a distance greater than a few yards and the most common devices in operation are electromagnetic or magnetic devices which require the use of a walk through portal, such as those used at airports. The USDigiComm invention will not only detect a concealed weapon but, as the company boasts, also has the capability of identifying the type of weapon.

Armed Robots

Armed robots are also being developed for use as combatants. The first military application for Foster-Miller Talon robots was explosive ordnance disposal, a role in which they have been used in Bosnia and are currently in service in Afghanistan and Iraq. The Talon can also be equipped with an M16 rifle, M240 or M249 machine-guns or Barrett 50-calibre rifles and used for armed reconnaissance.

A prototype Swords (Special Weapons Observation Reconnaissance Direct-action System) robot was delivered to the 3/2 Stryker brigade for evaluation, and successfully tested in Kuwait in December 2003. Additional prototypes have been manufactured and delivered to the Army Ardec for evaluation. The US Army is also evaluating alternative weapon fits, including 40 mm grenade launchers and M202 anti-tank rocket launchers.

In February 2005 Carnegie Mellon University's National Robotics Engineering Consortium and United Defense were selected to develop the Gladiator tactical unmanned ground vehicle for the US Marine Corps.

In September 2003 United Defense was selected for the task of designing and developing two Armed Robotic Vehicle (ARV) variants intended to reduce soldier exposure in high vulnerability reconnaissance and assault missions. The ARVRSTA variant is being designed to provide reconnaissance, surveillance and target acquisition for the Future Combat System Units of Action, while the ARV-Assault variant will provide direct and indirect fires to support mounted and dismounted operations (see Robot Wars Armada International 4/2005 for more details on ground robots).

In March 2005, Metal Storm announced that it had completed a series of live fire demonstrations held at the US Army's range facility at Picatinny Arsenal in New Jersey. These involved multiple live firings of a purpose-built version of the Metal Storm 40 mm weapon system mounted on a Talon unmanned ground vehicle (UGV).

The vehicle was equipped with a four-barrel array loaded with four rounds per barrel and an optical targeting system able to provide two-axis control and stability. It successfully engaged a variety of targets, including simulated personnel, an infantry carrier and a bunker with pyrotechnic rounds.

Better Small Arms

In the US Army, some units have replaced their M16A2 rifles with the shorter and handier M4 and M4A1 carbines, while the standard M249 light machine gun is being phased out in favour of a paratrooper model with a barrel as short as that of the M4 carbine.

Such compact weapons may be easier to handle in the confined spaces within vehicles, bunkers, and buildings, but the shorter barrel reduces the muzzle velocity of the 5.56 mm round. As a result the bullet loses the velocity-generated fragmentation effect (an important factor in its lethality) at a relatively short range.

Combat experience in Afghanistan and Iraq has shown that the current 5.56mm Nato round lacks stopping power, particularly when fired from short-barrelled weapons such as the M4/M4A1 family of carbines. One attempted solution was the Mk 262, Mod 0 and Mod 1 cartridges, which replace the standard four-gram SS109 bullet with a heavier five-gram projectile.

Working with the US Army, Remington has now developed the 6.8 x 43 mm Special Purpose Cartridge, while Barrett Firearms has created a new upper receiver that can be fitted to existing M16 or M4 weapons, converting them to the new calibre. This upgrade is made possible by the fact that the new cartridge has the same overall length as the 5.56 mm and is of only slightly larger diameter. The new round gives improved performance and lethality and is better matched to the demands of CQB (Close Quarters Battle) and urban warfare operations. For the moment, there is no plan to switch to this calibre across the board, but it is being used to boost the firepower of Special Forces and selected front-line combat units.

In December 2004 MTC Technologies Land Forces Group announced that it had developed a new rifle sight that would allow soldiers to fire around corners, over or under barriers, and into buildings using a variety of off-angle firing positions, with only the hands and forearms exposed. Suitable for use on any weapon that has a Picatinny 1913 rail weapon mount, the Parascope Urban Combat Sight incorporates a five-sided prism and has viewing ports from the rear for normal firing, and from the side for indirect firing. It does not interfere with normal operation when left on the weapon. Development was funded by the US Army's Communication-Electronics Command and Darpa. Currently under evaluation, the new sight could be fielded late in 2005.

As its name suggests, the Israeli company Corner Shot specialises in systems that allow soldiers to view targets 'around the corner' through a small video camera attached to the barrel of a weapon. The latest product to be announced is Corner Shot 40, which can be fitted to 40 mm grenade launchers. The video camera allows the user to scan around corners or into doorways, viewing the imagery on a liquid crystal monitor mounted in the rear section of the system, or transmit the image to nearby units, to a rear area command post or a central command.

To supplement its trained snipers, the US Army is using what it terms squad-designated marksmen. At first it equipped these with 7.62 mm calibre M14 rifles, but returning this 1960s era weapon to front-line service created logistic and training problems. By modifying the current 5.56 mm M16A4 rifle, the Army has created the Squad Designated Marksman Rifle. This incorporates a heavier match-grade barrel, a two-stage trigger and folding bipod legs. It is used with match-grade 5.56 mm ammunition.

Specialised Weapons

As events in Iraq and the Israeli occupied territories show, there is a role to be played in urban warfare by non-lethal weapons or other riot control technologies. However, this is a specialised field in which there are many development efforts underway, so cannot be covered in a general discussion on urban warfare.

In April 2005, Alliant Techsystems delivered the first six prototype XM25 advanced airbursting weapon systems to the US Army for field testing. This fires an air-bursting 25 mm HE round. The fire control system of the XM25 is based on a laser rangefinder, and loads the target range into the chambered round. The projectile estimates the distance it has flown by counting the number of revolutions it makes. This information allows it to detonate at a precise point along its trajectory, defeating enemy personnel sheltering behind a wall, inside a building or in a foxhole. Maximum range is more than 500 metres.

Israeli operations within the towns and refugee camps of the Gaza Strip have spurred the development of specialised munitions for use against buildings and bunkers. Rafael's Simon known as the Rifled-Launched Entry Munition in US service consists of a shaped-explosive charge in a plastic housing that incorporates a nose-probe-mounted detonator and a stabilising tail. It is designed to blast down a door. For harder targets, the company offers the wall-breaching standoff munition. This is able to blow a man-size hole in layered brick walls.

Israel Military Industries has developed the Shipon, a 100 mm calibre weapon able to carry an anti-tank/anti-fortification warhead able to penetrate up to 800 mm of armour or an anti-fortification/anti-personnel warhead that is designed to explode inside a building. In its basic form the Shipon cannot be fired in enclosed spaces, unlike the follow-on Shipon-UT based on a gas-tight modified Davis system.

AFVs Better Suited

US Army M1A2 Abrams tanks are receiving an urban-warfare upgrade in the form of the Tank Urban Survival Kit (Tusk). This will install a series of improvements, some of which are still in development. Designed for traditional armoured warfare, the M1 Abrams assumed that the primary threat would always be in the front sector, "but today it's a 360-degree fight", says Tusk product manager Lt. Col. Michael Flanagan.

The first Tusk component to reach the field has been the loader's armoured gun shield, which provides protection to the loader when the soldier is firing the 7.62 mm machine-gun from the turret. By March 2005 about 130 shields had already been purchased and sent to units in Iraq. The loader's firing position is also receiving a thermal sight, allowing the machinegun to be used in the dark. A system that allows the loader to fire the gun from inside the turret, while seeing the thermal sight's image, is under development.

Also under development are improvements to the commander's station outside the turret, although different systems are necessary for the M-1A2 Abrams and its older M1-A1 brethren. "Because of things we added to the turret in the A2, the commander's station had lost the ability to shoot the .50 calibre machinegun while under armour," explains Flanagan. <<We're developing a remote weapons station that will probably be similar to the one used on the Stryker to allow that weapon to be fired from inside the turret.>>

Explosive reactive armour similar to that used on the Bradley will be fitted to protect the tank's sides, while slat armour will be added to protect the vehicle's rear. Both modifications are intended to counter rocket-propelled anti-tank grenades.

A tank/infantry telephone will be installed to allow nearby infantry to communicate with the tank crew (see second section: Please Tell Me!).

Most of these add-ons will be incorporated into a kit, first examples of which could be deployed later this year. Installed in the field, they could be removed before a tank unit leaves the theatre of operations and left there to be used by the next Abrams unit deployed to the area.

There are two schools of thought on the best type of AFV for use in urban environments. Wheeled vehicles have a higher mobility than tracked designs, and have proven popular for peacekceping operations. However, they are more vulnerable than tracked vehicles.

In its normal form, ERA can pose a danger to nearby infantry and civilians. The development of Composite Lightweight Adaptable Reactive Armour (Clara) by Dynamit Nobel shows a possible solution--instead of using steel plates to sandwich the explosive fill, Clara uses plates made from plastic composites.

Active Protection Systems have their own disadvantages. Like ERA, counter-munitions fired against incoming threats may pose a danger to bystanders, while systems based on electronic countermeasures may not take effect fast enough to decoy or deflect threats fired against them at short range.

The Darpa is developing better ways of protecting vehicles from RPG attacks. It has developed an advanced, lightweight bar armour to protect US Marine Corps Hummers and is testing novel, high-strength nets intended to stop RPG and mortar rounds. For the longer term, Darpa's Iron Curtain project will develop and test a close-in weapon system able to shoot down incoming RPGs and missiles, though the bullets fired to achieve this may pose a collateral damage problem in urban conditions.

The General Dynamics Stryker infantry carrier was fielded operationally in Iraq in September 2003, and around 300 are reported to be in service there. The vehicle seems to be popular with its users. Since it is quieter than a tracked vehicle, it gives the enemy less warning of its approach.

To provide the Strykers with greater protection they have been fitted with protective slat armour. Known as the 'bird cage', this in intended to prematurely trigger the fuze of rocket-propelled grenades. A December 2004 internal US Army report that leaked to the press cited problems with this add-on armour, saying that it was effective against only about half of the RPGs fired at the vehicle. However, press reports say that this finding is distorted by an Army judgement that the 'bird cage' has failed if fragments from the exploding warhead strike the main armour, even if the latter is not penetrated. However, the slat armour adds an extra 2300 kg to the vehicle's combat weight, a load that is reported to strain the vehicle's engine and create problems with the automatic tyre pressure system.

The traditional primary role of a tank is to engage other tanks at long range. For this reason the ammunition load is normally biased towards armour-piercing, fin-stabilised discarding sabot (APFSDS) rounds. For urban warfare, the target is unlikely to be another tank, while high explosive (HE) ammunition, including high explosive squash head (Hesh) or high explosive plastic (Hep) would be the weapon of choice for use against buildings and bunkers. Thermobaric ammunition may be more effective than conventional HE rounds in killing personnel inside buildings or bunkers.

During combat operations in Iraq, US Army M1 Abrams tanks found two 120mm rounds to be effective tools for urban warfare--the M908 and the M1028. The M908 round was created by replacing the existing dual-mode (proximity and impact) fuze of the M830A1 with a hard steel nose that allows the projectile to penetrate an obstacle before detonating. It can be used to destroy concrete obstacles, clearing the way for the infantry and fighting vehicles to advance.

Fired from the 120 mm tank gun, the M1028 120 mm Canister Tank Cartridge releases a payload of 1100 tungsten balls that provide a shotgun-like effect. Intended to be used against massed assaulting infantry armed with hand-held anti-tank and automatic weapons at close range, the M1028 was designed to defeat 50 per cent or more of a ten-man squad with one shot and a similar proportion of a 30-man platoon with two shots. The Army asked that the round be effective against targets at ranges of 200 to 500 metres and ideally at 100 to 700 metres. In January 2005, General Dynamics Ordnance and Tactical Systems was awarded a $ 5.8 million fixed-price contract for low-rate initial production of 3600 rounds.

These are not the only 120 mm rounds to be designed with urban warfare in mind. While Israel is reported to be using its local equivalents of the M908 and M1028 during counter-insurgency operations in the Gaza area, it is also believed to be using an Israel Military Industries (IMI) 'stun cartridge'. Designed to create a high level of noise and pressure/blast at ranges of up to 30 metres, it can be used to suppress sniper fire from buildings or disperse hostile civilians trying to approach the tank.

In March 2004 the US Army Tank-Automotive and Armaments Command began a search for a new round able to defeat light and medium vehicles, buildings, bunkers and double reinforced concrete walls with low collateral damage. The warhead would have no explosive fill or fuze, but was expected to obtain its explosive effects by using hydrostatic shock to couple non-explosive energy. Being inert, it would avoid the safety problems associated with the M830A1 and its M908 derivative, and improve the combat survivability of light vehicles from which it was fired.

To replace the M908 and M1028, along with the M803A1 HE round and M393A3 105 mm Hep-T round, the US Army plans to develop the XM1069 Line-Of-Sight Multipurpose round. Suitable for use against hard targets such as bunkers, buildings and vehicles it will also have an anti-personnel role.

The XM1069 will be fitted with an Ardec-designed multi-mode fuze offering impact, impact/delay and airburst (time) modes. Full-bore (120 mm) and sub-calibre projectiles are envisaged. Both would be fin-stabilised.

The design of traditional MBTs is not well matched to urban conditions. For a start, the long gun barrel needed to drive an APFSDS round up to high muzzle velocities may be a distinct disadvantage in cramped surroundings. A more significant problem particularly for MBTs of Russian origin--is that limited depression angles prevent the barrel from being aimed at short-range targets located near ground level. A high elevation angle would also be useful when engaging short-range targets on the upper floors of multi-story buildings, or delivering indirect fire against threats behind buildings.

Given that MBTs must still be able to counter the threat posed by enemy armoured vehicles, the traditional tank gun and APFSDS rounds seem assured of a long-term future, but today's limited budgets effectively rule out the development of tank variants optimised for urban warfare.

Surprisingly, this has not been the case in cash-strapped Russia. During the fighting in Grozny, the Russian Army had to use ZSU-23-4 Shilka self-propelled quadruple 23 mm air-defence cannons against high-elevation targets that could not be engaged by tanks. To provide a longer-term solution, the Uralvagonzavod Machine Building Plant used the T-72 as the basis of the new BMPT tank support combat vehicle.

Protected by add-on explosive reactive armour, this is armed with a turret carrying one or two 2A42 30 mm automatic cannon able to fire at elevations of up to 45 degrees, a coaxial 7.62 mm machine gun and four launchers for Ataka (AT-9) anti-tank guided missiles. Two forward-facing AG-30 30 mm automatic grenade launchers are mounted on either side of the driver.

A practical compromise might be the installation of secondary armament selected with urban warfare in mind. Israel's Merkava has a 60 mm breech-loading mortar able to fire high explosive, smoke and illumination rounds for engaging enemy anti-tank teams and helping to conserve main gun ammunition. On the Merkava Mk 1, the mortar was externally mounted, but on subsequent models it is mounted in the left side of the turret roof and can be loaded and fired from within the turret. Israeli officials have hinted that the Merkava Mk 4 variant could also be fitted with special purpose and non-lethal weaponry for urban warfare operations.

Any light, self-propelled anti-aircraft gun system has the potential to be used against ground targets. Early in 2005, the US Army's 3rd Cavalry Regiment was reported to have modified eight Boeing Avenger self-propelled anti-aircraft missile systems to allow them to be used as gun trucks in Iraq. Army engineers removed the right-hand Stinger missile pod, then remounted the vehicle's 0.5-inch machine-gun in place of the pod and increased the weapon's ammunition load from 250 to 600 rounds.

In the original configuration, the machine-gun cannot be depressed sufficiently to fire at front-sector ground targets. Changes were made to the fire control software, allowing the flir and laser rangefinder to be used to direct the machine-gun against targets in any direction and at any elevation.

More Accurate Weapons

To provide its Iraq-based artillery units with a 'smart' projectile, the US Army plans to speed up the service introduction of the Excalibur 'smart' 155 mm artillery round by approximately 15 months, and in doing so hopes to equip several brigades by March 2006. This will be done by curtailing service testing, and by sending the first rounds to combat units rather than training units.

Israel Aircraft Industries' MBT Missiles Division developed the Fireball 120/121 mm 'smart' mortar round specifically to meet the needs of urban combat. The round flies a ballistic trajectory after launch. Around the peak of its trajectory, it will switch to a gliding path under the control of an on-board Global Positioning System (GPS) system. Once the bomb's semi-active laser has acquired the target (which must be designated by a ground-based or airborne laser), it will begin a steep terminal dive, a trajectory intended to minimise collateral damage in an urban environment.

Infantry-operated anti-tank missiles are being widely used as "portable artillery' by front-line units. In 21 of the 28 major battles fought since the early 1980s, antitank missiles were used not against tanks, but against vehicles, trucks, buildings, mud huts, bunkers, caves, small boats and even individual snipers. Recognising this trend, the US Department of Defense now uses the term 'close combat missile systems' rather than 'anti-tank' missiles.

MBDA sees semi-active command-to-line-of-sight (Saclos) missiles as being better suited to non-MBT targets than the imaging infrared guided missiles such as the Raytheon Javelin and Rafael Spike/Gill. It is now offering the new Saclos-guided Milan Extended Response. Ruag is currently developing a new range of weapons particularly well suited for urban warfare. The first is a new tandem warhead for the Milan (although neither Ruag nor MBDA admit this as being an official development) that has a main charge using a cast molybdenum liner. Recent tests witnessed by Armada International's Editor-in-Chief proved that the warhead was able to easily defeat up to 1.5 metres of rolled homogeneous armour.

Returning to the new all-digital Milan firing post, the unit will be able to handle all earlier models of Milan, including the Milan ER, and will allow remotely controlled firing. In close-quarters and urban combat this will improve the survivability of the firer.

Other munitions developed by Ruag include the 81 mm Mapam mortar bomb, the Crad vehicle-launched grenade and the Mep penetration warhead. The Mapam 81 is in fact a derivative of the 60 mm Mapam, but expels a mix of approximately 4800 steel balls of 4 and 6.2 mm in diameter. Because the balls are embedded in the bombs composite material body there are no other fragments than the balls, which means that their speed, penetration capability and range are perfectly determined and consistent. The 60 can be safely fired at a minimum range of 70 metres and the 81 at 100.

The Crad uses the same design, but applied to 76 mm anti-personnel grenades. Launched from the vehicle they explode at a range of about 45 metres and at a height of between seven and two metres on their downward trajectory to expel a shower of steel balls, but only ahead of them. Dismounted vehicle followers thus remain totally safe.

The Mep is a wall penetrator that is designed to fit anti-tank shoulder fired weapon warheads such as the AT-4, Panzerfaust and RPG7 without altering the ballistic trajectories of the original munitions. Recent firings conducted just after those of the Mapam and Crad showed that the Mep was able to penetrate 20 cm of double reinforced concrete and then explode. Because the Mep penetrates the wall without setting off any charge whatsoever, it can be safely fired at a range of 50 metres. While it will disable people within the aimed area of a building, it will not harm those (like hostages or innocent civilians) located in a neighbouring room. Ruag is also actively working in the area of what it terms "Starblast Technology", which is a softer designation for an optimised and better-controlled hybrid thermobaric warhead that emphasises overpressure rather than high temperature. This could find useful urban warfare applications in penetrators, but also in roof-attacking weapons. Ruag is in the process of becoming the leading European warhead specialist as it already supplies warheads for the Tow, Nlaw, Bill 2 and Milan missiles amongst many others

In a rather ironic twist of events, after a period during which the trend for fire-and-forget weapons was all the rage, it is now realised that the Javelin is not the anticipated panacea in an urban environment. So much so that the US Marine Corps has recently unearthed the Predator missile in its Sraw-Multi-Purpose version, production of which had been cancelled in 2003. To fulfil an urgent requirement from the Corps, Lockheed Martin has converted 400 Predators for urban assault in Iraq with a blast warhead optimised for breaking walls and dealing with the lighter types of armoured vehicles.

Longer-ranged tactical weapons now under development, such as the Lockheed Martin Joint Common Missile (JCM) and the Raytheon Principal Attack Missile (Pam) and Loitering Attack Missile (Lam), on the other hand will also be useful in future urban combat. The fast transfer of target information envisaged under network-centric warfare will allow missiles to be directed against a target as soon as it is located. The Pam and Lam will be able to fly to the reported position of the target, and then fly a diving attack.

On 10 May 2005, France, Sweden and Britain agreed to pool their technology demonstration programme funding on a next-generation missile. MBDA hopes that the study will result in a common requirement for a new missile to be developed by the three nations, perhaps in partnership with Germany, Italy and Spain. Development of what MBDA terms the European Modular Munition (EMM) could run from 2009 to 2014, allowing the resulting weapon to enter service around 2015.

The company is studying a combination of imaging infrared and semi-active laser designation for terminal homing. As the missile approaches the target area, the missile's seeker would generate infrared imagery of the target zone. A ground-based or drone-mounted laser designator would then be used to illuminate the target for a few seconds--long enough to allow a wide-angle semi-active laser channel to locate the marked target, allowing the missile to re-centre the field-of-view of its imaging channel, then begin final homing.

The latest generation of 'smart' bombs can use lighter warheads than the 454-kg and 907-kg 'iron' bombs that were the traditional candidates for receiving add-on guidance kits. This trend is illustrated by the GBU-38 version of the GPS-aided Jdam, which is based on a 500 lb (227 kg) bomb, and by the Boeing Small Diameter Bomb, which is based on a 250 lb (113 kg) bomb. The GBU-38 completed its initial operational evaluation on 28 September 2004, and was declared operational on 8 October. On 29 October, the US Navy made the first combat launches.

Testifying before the Senate Armed Services Subcommittee on Strategic Forces on 16 March, 2005, Lance W. Lord, Commander of the US Air Force Space Command, described how during 'Operation Vigilant Resolve', the First Marine Expeditionary Force in Fallujah was able to call in precision air strikes against individual buildings and structures. "We used a combination of persistent Intelligence, Surveillance and Reconnaissance assets, on-call strike aircraft and Global Positioning System satellites to create stunning precision strikes against individual structures in dense urban areas", he told the Subcommittee.

An even more dramatic approach to reducing collateral damage is illustrated by the US Air Force's HardStop (Hardened Surface Target Ordnance Package). This is a GPS-guided bomb that will dispense 54 smaller bomblets in a pattern that can be programmed to cover a radius of anything from 3 metres to almost 17 metres. The individual bomblets arc designed to penetrate the roof of a building and explode inside, confining most of its destructive effects to within the building. Some of the bomblets can be programmed to go through one or more floors before exploding, thus spreading the weapon's lethal effects over the height of a multi-storey building. The HardStop has been tested at Eglin Air Force Base in Florida and is expected to become operational in Iraq later this year.

Worst Kind of War

The three-dimensional maze of urban operations is probably the worst logistical problem a commander can face. But city fighting is not the only problem faced by the Israeli forces in the West Bank, and US-led coalition forces in Iraq. Tactics and technology that focus only on overcoming the disadvantages of urban fighting may be missing the point. These are counter-insurgency operations, and share the characteristics of what Greg Wilcox and Gary Wilson have identified as 'fourth generation warfare'. In a May 2002 article 'Military Response to Fourth Generation Warfare in Afghanistan', they warned that, "Fourth generation warfare is manifesting itself in highly compartmentalized, cellular, predatory networks operating outside the framework of nation-states. How do we counter and win against a formless foe? In fact, how do we know when we have won?"

Unexpected Demands

Urban warfare also makes heavy demands on supplies of all kinds. Cities are warmer than the countryside, and soldiers need more drinking water, as well as a high-calorie diet to compensate for the exertion needed to fight in buildings. More medical supplies are needed, particularly if soldiers must fight in sewers or other unsanitary environs, while uniforms and equipment wear out more quickly. As well as body armour and helmets, urban soldiers need additional protection, including knee and elbow pads, heavy gloves and ballistic eyewear to reduce the risk of injury.

Thinking 'Spherically'

Finally, urban warfare tactics require thinking in three dimensions, what US National Security Analyst C. L. Staten calls <<spherical>> security. Some of the rules of three-dimensional warfare include:

* wherever possible, attack the upper floors and work downwards

* exploit high positions for observation and positioning snipers

* position stay-behind forces to make sure the enemy doesn't re-enter cleared buildings.

FM 3-06.11, the 2002 US Army Field Manual on combined arms operation in urban terrain, contains detailed instructions on moving through the three-dimensional landscape and recommends avoiding doors and windows and clearing rooms and hallways with a grenade before entering. One piece of advice suggests another good reason for attacking a building from above, which is 'Throwing fragmentation grenades up a stairway has a high probability for the grenades to roll back down and cause fratricide.'