ETHNIC CONFLICT : The Serb and Croat Square Off : Milosevic vows to hold Yugoslavia together and preserve the status quo. Tudjman promises his people independence. Something has to give.

A popular joke holds that Serbia’s Communist strongman, President Slobodan Milosevic, and his nationalist counterpart from Croatia, Franjo Tudjman, are on the deck of a ship off the Adriatic coastline when a tidal wave washes both overboard.

“Who would be rescued first?” the joke asks.

The punch line: “Yugoslavia.”

As the 73-year-old federation disintegrates amid civil war, blame for the intractable conflict between Serbs and Croats is being laid squarely at the feet of their political leaders.

Milosevic rose to power three years ago by convincing fellow Serbs that they had suffered in the name of Yugoslavia, which reduced them to equals among the other ethnic groups they outnumber in the federation of 24 million. He vowed to make Serbia mighty again and restore the nearly 10 million Serbs to their rightful pre-eminence.

Tudjman won election last year by promising independence from the union that binds Croatia and Serbia, angering Milosevic who sees secession as a threat to Croatia’s 600,000 minority Serbs.

By trumpeting each other’s excesses and escalating the war of rhetoric to one of arms, the leaders have drawn Yugoslavia’s two largest ethnic groups into a deadly crisis from which there appears no way of escape.

While history may ultimately deal the same fate to Milosevic and Tudjman by holding them both responsible for the catastrophic results of their political brinkmanship, the civil war to which they have condemned their peoples has, so far, doled out a mismatch of punishment and reward.

Support for the Serbian leader has been bolstered in his republic because of the considerable success guerrillas have achieved in seizing Croatian territory. Despite the threat of massive casualties and economic ruin that will take at least a decade to overcome, Milosevic has seldom stood so high in the esteem of his people.

By contrast, Tudjman’s popularity among the 5 million Croats has eroded to a dangerous low. Political infighting within the ruling Croatian Democratic Union has forced him to sack his prime minister, defense minister, foreign minister and three top political advisers in recent weeks, leaving the often-pompous president badly shaken and vulnerable to a coup.

As in most conflicts, the political spoils have gone to the victor, and the boost for Milosevic is a direct result of Serbian guerrillas having trounced the ill-equipped Croatian forces in the war’s opening salvos.

Serbia seized 15% of Croatian territory and inflicted at least 200 fatalities before agreeing to an unenforceable cease-fire this week that effectively allows it to hold on to its territorial gains while getting ready for the next round.

The background and behavior of the two presidents would seem at first glance to suggest the opposite outcome from what has so far transpired.

Tudjman is a retired army general, whose brusque and decisive manner evokes the image of a warlord. Milosevic, whose career has been in banking and Communist Party bureaucracy, is reclusive and visibly uncomfortable in company other than that of his closest advisers.

That stylistic difference has proved significant in the current crisis.

Tudjman’s boastful self-assurance has left him open to criticism in Croatia for promising a swifter, easier independence than he has been able to deliver.

Milosevic has stayed above the fray with a strategic silence, giving opponents little to use against him.

Tudjman’s hold on power, which only a few months ago appeared unshakable, likely rides with his republic’s fortunes in the next stages of war.

How long Milosevic can use the war to his advantage remains to be seen. Western diplomats say Milosevic has deliberately exacerbated the conflict with Croatia to distract the Serbs’ attention from economic devastation that is the result of his nationalist indulgence.