WASHINGTON (AP) _ Any show of disunity by NATO allies in confronting Yugoslav President Slobodan Milosevic will embolden him to defy threats of air strikes that would punish him for breaking the Kosovo cease-fire accord, Balkan analysts warn.

``What Milosevic is doing is playing a strategic game; he's calibrating what the alliance and the Clinton administration is capable of mustering in way of a response at this stage,'' George Biddle, vice president of the International Crisis Group, said Wednesday. The group is an independent organization monitoring the peace process in the Balkans.

On Tuesday, the Yugoslav strongman sent packing NATO's two top generals who had gone to Belgrade to deliver a tough warning that the Yugoslav security forces had to stop attacking ethnic Albanian rebels in Serbia's Kosovo province.

Milosevic had left the two _ Gen. Wesley Clark, the allied commander in Europe, and Gen. Klaus Naumann, the chairman of the NATO Military Committee _ waiting for an entire day before receiving them.

On Wednesday, State Department spokesman James P. Rubin described the talks in Belgrade as ``deeply troubling.'' He said the Serbian leader's responses were ``unsatisfactory across the board.''

At least 2,000 people died and 200,000 were left homeless in seven months of combat in Kosovo between Yugoslav security forces and ethnic Albanian insurgents fighting for the independence of the province.

The conflict ended in a cease-fire in October after NATO had threatened to carry out massive air strikes against Serb targets.

But last week, at least 45 ethnic Albanians were killed in a village in southern Kosovo that had been under attack by the security forces.

When William Walker, the American head of a mission to verify compliance with the truce, accused the Serbs of responsibility for the massacre, he was ordered to leave the country, although Deputy Prime Minister Vuk Draskovic said Wednesday that issue might be resolved with a compromise.

Earlier, U.N. war crimes prosecutor Louise Arbour was barred from entering Kosovo when she tried to investigate the killings.

``If all that isn't poking your finger in the eye of the West, I don't know what is,'' Biddle said.

He noted that NATO credibility was now on the line and that strong U.S. leadership would be required to formulate a united response to Milosevic's ``provocations.''

Jim Hooper, head of the Balkan Action Council, a private Washington think tank that aims to educate the public on the Balkan crises, warned that Milosevic was bent on undermining NATO credibility before the alliance's 50th anniversary summit in Washington in April.

``I think he may be shooting Kosovo Albanians, but he's taking aim at NATO credibility and American leadership of the alliance,'' he said.

He said Milosevic apparently wastrying to do the same thing Iraqi President Saddam Hussein had accomplished with the international monitors in his country: ``neuter them or kick them out.''

``He has calculated that only decisive leadership by the president of the United States will be able to mobilize the NATO allies to intervene militarily, and he calculates that with the president's focus on his impeachment defense, Clinton will be too distracted to exercise leadership required to do that,'' Hooper said.