EDITORIAL HOMEGROWN TERRORISM GANG VIOLENCE IS THE DIRTIEST BOMB OF ALL.

THE U.S. Department of Homeland Security has a budget this year of $37.6 billion. This money will help the federal government, states and cities construct security measures at seaports and airports, for border checks and baggage screening and screeners and for explosive-detection devices. These and many, many other projects are designed to keep foreign terrorists from another sad day like Sept. 11, 2001.

But as we drop untold billions on preventing al-Qaida and other terrorist groups from carrying out some unknown future attack, we have effectively ignored a very real plague creeping across the nation and killing thousands of Americans every year right under our noses.

While we worried about dirty bombs set off over the holidays by people carrying almanacs, a quiet, but even dirtier bomb has been exploding all around us - the spread and growth of illegal street gangs.

More than half of the 500 homicides in Los Angeles last year were attributed to gang activity. Communities across the nation also see a significant portion of their reported killings and assaults as related to street gangs.

``This is what's killing young people here,'' Los Angeles Police Chief William Bratton said during a two-day summit on gangs attended by police chiefs and sheriffs from across the country.

So while the federal government has been appropriating money hand over fist to fight a shadowy, unknowable foe, Bratton and other police chiefs are fighting a foe that is in many ways more real, more deadly and more destructive to our country than foreign terrorists could even hope to be.

As part of the summit, the police chiefs are developing a national strategy to take to federal leaders in Washington, D.C., as a sort of blueprint for a comprehensive attack nationwide on gang activity, much like the coordinated attack on the mafia in the 1980s and 1990s. They hope to make a case that fighting gangs is worthy of funding and resources as well.

It is important to be prepared as much as is reasonable for another terrorist attack on this country. But we can't let that concern distract us from the things that affect our cities and neighborhoods and streets every day. And that is the threat of homegrown terrorists.

We don't need intelligence ``chatter'' to recognize how active gangs are in our city. Just a look at the graffiti, the teenagers crammed into detention facilities, the families living in fear is enough to know that we are already under attack.