Firebell in the night.

An End to Evil: How to Win the War on Terror, by David Frum and Richard Perle (Random House, 304 pp., $25.95)

THIS is a very solid introduction to serious thinking about the War on Terror and the scale of the threat to the United States. In one slender volume, Frum and Perle have outlined an analysis of the danger, a proposed strategy for victory, and a call for the dramatic transformation of many of the key institutions of national security. In judging how out of touch with reality the Democratic front-runners are, one need only read An End to Evil: There is more serious analysis and sound strategy in this book than in the policy positions of all the Democratic presidential campaigns combined.

Frum and Perle warn that "now comes the hardest test of all. The war on terror is not over. In many ways, it has barely begun." In contrast to Gen. Wesley Clark's ridiculous promise that if he is elected there will be no terrorist attacks, they admit that "defeats may well occur, for they too are part of war, and we shudder to think how some of our leaders in their current mood will respond." They speak some highly cautionary words: "We can feel the will to win ebbing in Washington; we sense the reversion to the bad old habits of complacency and denial." Watching the Democratic presidential debates, one feels that Frum and Perle are optimists: There is a substantial and noisy minority that would have the Eagle replaced with the Ostrich as the symbol of American character.

The ostrich-like nature of the isolationist Left is captured in this book's description of our enemies and their deadly serious intent to destroy our society:

   There is nothing new about terrorism.
   What is new since 9/11 is the chilling realization
   that the terrorist threat we thought
   we had contained within tolerable boundaries
   was not contained at all, menacing
   our well-being as a people, even our survival
   as a nation. This realization stems,
   first, from the scale of 9/11, and beyond
   that, from the apocalyptic vision of the terrorists
   themselves.... The terrorists kill
   and will accept death for a cause with
   which no accommodation is possible.

These few lines capture the heart of the first great foreign-policy debate of 2004, and it's not just a debate with Howard Dean and the isolationist Left. When General Clark--a putative centrist--asserts that "nothing is going to hurt this country--not bioweapons, not a nuclear weapon, not a terrorist strike--there is nothing that can hurt us if we stay united and move together and have a vision for moving to the future the right way," he is describing a view that is totally incompatible with the Frum-Perle thesis.

In fact, biological weapons are the greatest threat we face, a threat requiring new defense measures. An engineered virus (flu maybe even more than smallpox) or a well-designed anthrax attack could kill so many Americans--and spread such panic--that the impact on our society would be devastating. And the number of nuclear weapons that terrorists might acquire is far greater than most people realize, because there are more than ample supplies of nuclear material stored in research facilities and in power plants. Clark's assurances that Americans don't need to worry about these weapons as long as we are united is as misleading and dangerous as were Henry Wallace's promises in 1948 that Stalin and the Soviet Union were simply misunderstood by the Truman administration. The fact that Clark is a West Point graduate and retired four-star general makes his factually false reassurances vastly more damaging to American security than anything Howard Dean could say.

Whereas Frum and Perle are clearly worried and believe America is clearly in danger, Clark breezily proclaims that "if I'm president of the United States, I'm going to take care of the American people. We are not going to have one of these incidents." Frum and Perle know better. They know that we have active opponents who hate us and want to destroy us, and they make the powerful point that to whatever extent our intelligence agencies have underestimated the threat of weapons of mass murder and destruction, it actually makes the case for preemption more compelling. They argue (correctly, in my judgment) that if you believe you could lose hundreds of thousands or even millions of Americans if you wait, you have to be prepared to act decisively. The less you know, the more you have to err on the side of preempting a life-threatening and possibly nation-threatening act.

The recent revelations that both the U.S. and the International Atomic Energy Agency had seriously underestimated Iran's nuclear program for the last 18 years, and that Libya has now confessed to having a series of programs it denied for two decades, should be ample reminder that dictatorships lie and that denial and deception are practiced every day by our opponents. The further revelations that Pakistani scientists have almost certainly been involved in the Iranian program are a further reminder that so-called friendly dictatorships can be unstable and uncertain allies.

Of the Left's desire to wait and move cautiously, Frum and Perle note that "quite frequently, the real motive of those who advocate delay is the hope that if we postpone action, somehow the threat will disappear on its own. This isn't policy. It's fantasy." Thus in three short sentences they puncture the self-delusions of the Ostrich wing of American society. We aren't debating people on the Left who have serious policy differences. We are debating people who live in a fantasy world in which al-Qaeda is not really a threat.

These are bracing truths. And this is an important book, because it is willing to be blunt about who our most serious opponents are:

   That cause is militant Islam ... Yet for
   many reasons our leaders, and the leaders
   of other nations, have found it difficult to
   say so ... a radical strain within Islam has
   declared war on us. This strain seeks to
   overthrow our civilization and remake the
   nations of the West into Islamic societies,
   imposing on the whole world its religion
   and its law. To achieve these cosmic ambitions,
   Islamic terrorists wish--and are
   preparing--to commit murder on a horrific
   scale.

The book makes clear that the war we're engaged in is not a war between civilizations, but a civil war inside Islam, in which we have every interest in ensuring that the irreconcilable fanatics lose.

Because Frum and Perle are prepared to tell the truth about the nature of this war, they can move on to an intelligent discussion of the many changes that will be needed to win the war. And--despite President Bush's eloquent and consistently correct call-to-arms in a long war with terror--much of the Washington establishment still does not understand how big the challenge is. This war is going to be longer, bigger, and harder than most D.C. insiders think. It is going to require complex and profound transformations of most of our instruments of national security (far beyond the Defense Department). The war can be won, but only if we are willing to engage in a serious debate about it. Imagine trying to win the Second World War without a thorough appreciation of Nazism, Fascism, and Imperial Japan. Imagine trying to win the Cold War without an understanding of Communism. That is the burden the Washington elites have put on themselves. They want to win but without the kind of intense, passionate debate over the nature of the war that will be indispensable to victory.

Frum and Perle have done both America and the cause of freedom a real service by writing An End to Evil. Every serious citizen should read it and ponder its arguments.

Mr. Gingrich was Speaker of the House of Representatives from 1995 to 1998. He is currently a senior fellow at the American Enterprise Institute.