Who Could Have Done It

By PRISCILLA PAINTON

THE BOMBING OF THE WORLD TRADE CENTER COULD TURN OUT TO be the work of none other than a psychotic, mad-as-hell American -- a live version of the Hollywood revenge fantasy. But many aspects of the bomb, including its placement and force, carry the mark of more sophisticated hands. Experts who study terrorists around the world have begun to speculate about several groups:

THE BALKAN FACTIONS

Of the 19 callers who took responsibility for the bombing, at least one said he spoke for an organization calling itself the Serbian Liberation Front. Another claimed to represent Croatian militants. Still another called in the name of Bosnian Muslims. The possibility of a Balkan connection was made more tantalizing by the fact that a bomb was defused on Friday near the U.S. embassy in the Croatian capital of Zagreb.

Most of the Balkan nationalities have a history of marrying politics with violence. It was the murder of Archduke Francis Ferdinand and his wife in Sarajevo by a Serbian youth that set off World War I. And according to a French expert on the Balkans, Xavier Raufer, the terrorist techniques that the Palestinians and the Lebanese made notorious in the past two decades -- bombings, kidnappings, hijackings -- were virtually invented by Balkan groups. "These guys make Abu Nidal look like Mother Teresa," he says.

Militants seeking independence for Croatia have struck inside the U.S. in the past. In December 1975 Croatian nationalists were suspected of planting a bomb in a luggage locker at La Guardia Airport, killing 11 people and injuring 75. Less than a year later, Croats hijacked a TWA jet traveling from New York City to Chicago and eventually diverted it to Paris. As part of that operation, the group also planted a bomb at Grand Central Terminal, which killed a police officer who tried to defuse it. In June 1980 Croatian "freedom fighters" detonated a bomb inside the museum at the Statue of Liberty, but no one was injured. All told, Croats committed more than 20 acts of terror in the U.S. from 1976 through 1980.

Croatia has achieved a shaky independence since then, albeit one marred by episodes of urban shelling by Serb guerrillas. The Croats could conceivably have been motivated to carry out the attack hoping the Serbs would be blamed. But the Serbs have their own reason for staging the bombing -- or for doing it and hoping the Croats would be blamed. The announcement this week that the U.S. would soon start sending relief flights over Bosnia made it just as plausible that the blast might be a response by Serbs to a perceived tilt against their side. Six months ago, Serbian nationalists threatened to bomb Western's Europe's nuclear facilities if its governments intervened militarily in the former Yugoslavia.

The Bosnian Muslims too have reason to play a part in the Balkan blame game. They have been known to bomb their own people in Bosnia, hoping the Serbs and the Croats would be held responsible and Western allies would intervene on their side. But they are also angry at the Clinton Administration for refusing to lift an arms embargo despite earlier pledges to do so.

PALESTINIAN FACTIONS

An extremist group called Hamas has been virulently opposed to the current Middle East peace talks, and last week's bombing could have been an attempt to % torpedo the negotiations before they resume next month. In addition, it was Hamas supporters who made up most of the 400 or so Palestinians whom Israel expelled late last year and who now languish in the no-man's-land between the Israeli and Lebanese lines.

IRAN, IRAQ, LIBYA

February was the second anniversary of the U.S.-led ground attack against Iraq; setting off a bomb at the center of America's largest city could have been Iraq's way of marking the date. But since Clinton took office, Iraq has been making conciliatory noises, as has another of the U.S.'s longtime enemies, Iran. However, there is no shortage of fundamentalist groups, including the Iranian-backed Hizballah, that might seek to punish the nation they regard as "the Great Satan."

RUSSIAN NATIONALISTS

Long-shot culprits to be sure, Russian nationalists who want to install a reactionary, law-and-order regime in Moscow have blamed much of their country's troubles -- from corruption to economic chaos and crime -- on Western, and mainly U.S., influence. They have stepped up their attacks on Boris Yeltsin in recent months, forcing him to distance himself from free marketeers and from his Western-oriented diplomacy. But so far he has survived their challenges. In frustration, his enemies might have sought expression on American soil.

With reporting by William Mader/London and Thomas A. Sancton/Paris