MOSCOW — A TINY and once-obscure mountain republic at Russia's southern edge has become one of the most important obstacles to Boris Yeltsin's reelection next summer.
As the war in separatist Chechnya has reignited in the past three months, Russian public opinion has only hardened against the continuing use of force, according to pollsters here.
''Support for the war, and for pursuing a victorious end to the war, is very low now,'' says Yuri Levada, director of the All-Russian Center for the Study of Public Opinion in Moscow.
In the latest escalation, rebel troops attacked the Chechen capital, Grozny, last week. They seized much of the city, killed at least 200 Russian soldiers, and cut off water and electricity in the city before they were pushed out again. Fighting has continued into this week.
Such skirmishes keep reminding Russians that no end is in sight for the war Mr. Yeltsin launched 15 months ago.
At most, only about 20 percent of Russians support the use of force in Chechnya, while two-thirds want the troops to withdraw, says Mr. Levada, who surveys Russians on the subject at least once a month. As many as 40 percent would be willing to grant independence to Chechnya to end the war. Another 40 percent still oppose letting Chechnya leave the Russian Federation.
But independence is one option that Yeltsin will not consider in trying to end the war before presidential elections in June. The fundamental issue for Yeltsin - and for many other Russian politicians - is maintaining Russia's territorial integrity.
Russia has laid claim to all or part of Chechnya - on the northern side of the Caucasus Mountains between the Black and Caspian Seas since the reign of Peter the Great in the 18th century. The relationship between Russians and Chechens, who have lived in the area since at least 3,000 BC, has been hostile in varying degrees ever since.
Russians allowed the Soviet Union to dissolve in 1991, granting independence to its republics, but Chechnya remained part of the Russian Federation. Since then, says Sergei Yushenkov, a deputy in the Russian Duma, or lower house of parliament, and former chairman of the military committee, ''our main problem has been the consolidation of our union.''
Since the Russian Constitution offers no basis for secession from Russia, Mr. Yushenkov says, to allow it would be a blow to Russian statehood itself.
''Separatism is a terrible plague of our time,'' he says. Americans fought a civil war against it, he notes, and would not happily allow the secession of, for example, Alaska today.
He also notes, however, that ''there are civilized and uncivilized methods of dealing with separatism. Russia chose uncivilized methods.''
The method was a full-scale military assault that began in December 1994, two years after Chechen leader Gen. Dzhokhar Dudayev declared Chechnya to be independent. By a 2-to-1 margin, Russians blame Yeltsin for the war rather than General Dudayev, according to Levada. So for Yeltsin to let Chechnya go now would be to accept a costly failure.
''As with Afghanistan,'' says Nicolai Petrov, a political scientist with the Carnegie Endowment for International Peace in Moscow, ''it's easy for a new president to say it was a mistake and leave,'' but not the president, who bears responsibility for the mistake.
But even Yeltsin, Mr. Petrov surmises, would gain more than he loses in public favor by withdrawing troops - even if it meant giving Chechnya independence. Levada, the pollster, agrees. ''A bold decision about withdrawal would probably be his best option, but it would be seen as a defeat,'' he says.
One factor slightly to Yeltsin's advantage is that his main election rival, Communist candidate Gennady Zyuganov, does not support any of the steps that would clearly end the war either.
Yeltsin and his staff argue that withdrawing Russian troops would free Chechen rebels to wage a war of their own on Chechen civilians. That fear might be realistic, but the Rus sian troops have already killed tens of thousands of Chechen civilians, according to Russian human rights monitors.
''If the choice is between continuing this war without visible success or giving them independence,'' Petrov says, ''I think the public favors the latter.''
Yeltsin assigned two government commissions to cull through options on how to end the war. Their reports were due this week, but appear to be delayed.