WITH SERBIAN forces defeated and out of Kosovo, it might seem odd to speak of a threat posed by their leader, Slobodan Milosevic. But U.S. Gen. Wesley Clark, an authoritative source, warns against complacency. The Serbian Orthodox Church has commendably called for the president's resignation, and remarkable crowds are rallying against him in provincial cities. Mr. Milosevic is on the defensive. But he retains considerable resources with his control of the secret police and his skill at dividing, intimidating and buying off his opponents. "He is simultaneously preparing forces, gathering intelligence and capable of moving against President Djukanovic in Montenegro," Gen. Clark, NATO supreme allied commander, told a Senate committee last week.

This matters to the United States. As long as Mr. Milosevic is in power, there will be no stability in the Balkans and little prospect of drawing down U.S. troops. "When he's removed, and the international community reasserts itself inside Yugoslavia, bringing Yugoslavia into the democratic community of nations, I think many things will change very quickly in the Balkans," Gen. Clark said.

One essential policy is continued and heightened U.S. and NATO support for the democratic government of President Milo Djukanovic in Montenegro, one of the two republics (the other is Serbia) remaining in Yugoslavia. Montenegro is much the smaller partner, but it is crucial as a haven, model and inspiration for Serbia's fractured democrats.

The other essential policy is support for those democrats. The anti-Milosevic forces lack a credible leader, they lack self-confidence, they lack unity. But these weaknesses need not be eternal. President Clinton rightly has ruled out reconstruction aid to Serbia as long as Mr. Milosevic remains in power, but that should not rule out creative assistance to the political forces seeking to put Serbia on a new path.

"A terrible wrong has been done," Gen. Clark said, referring to Serbia's crimes against the people of Kosovo. "That wrong has to be faced. It has to be openly acknowledged by the Serb citizenry, by their leadership, by the church and others." Delivering Mr. Milosevic to the international court in The Hague will be an essential step in that process. The West should do whatever it can to help Serbs who understand that requirement.