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...