MOSCOW -- In saber-rattling warnings to its neighbors, Russia declared yesterday that it would use its military might to protect the lives of Russians living throughout the troubled nations of the former Soviet Union.
President Boris N. Yeltsin, his face stony with anger and determination, told Moldova on his return from the United States and Canada that, while Moscow wanted a negotiated settlement of the growing ethnic conflict there, it was prepared to intervene militarily to protect Moldova's Russian population.
"We want to settle all matters at the negotiating table . . . but when dozens of people are killed and when there is a war going on, we cannot remain idle, especially when it is happening on our borders," Mr. Yeltsin said.
"In this case, we must react to defend people and to stop the bloodshed," he said. "We have the strength to do that."
Similar warnings were directed to Georgia, another former Soviet republic, whose forces are attempting to restore its rule in Southern Ossetia where residents are seeking unification with the Russian region of Northern Ossetia.
The tough talk -- coming not only from Mr. Yeltsin but also from Gen. Alexander Rutskoi, his vice president, and in a series of Cabinet statements over the weekend -- made it clear that Russia was ready to use its considerable military capability in these spreading ethnic conflicts.
The initial responses from Moldova and Georgia were that they wouldnot be intimidated by Russia. They rejected the Russian warnings as interference in domestic Moldovan and Georgian affairs, and they dismissed Mr. Yeltsin as a bully.
Moldovan President Mircea Snegur accused Mr. Yeltsin of "imperialist aspirations" and charged Russia with supporting "authoritarian, neo-Communist regimes" solely on the basis of their professed loyalty to Moscow.
Mr. Yeltsin, upon returning to Moscow yesterday, said that Russia had the military strength to impose its will in Moldova and added, "Let Snegur know that."
In Georgia, Eduard A. Shevardnadze, the former Soviet foreign minister who now heads the country's governing council, supported the Moldovan statement, which accused Moscow of refusing other nations "the right to build their lives as they wish."
Mr. Shevardnadze said in an open letter to the Russian government that General Rutskoi's statements had "sharply worsened the situation in Georgia" and could incite further bloodshed there.
But Russia and Mr. Yeltsin himself face a clear test of their authority, and the sheer emotion involved in the predicament of Russians caught outside their homeland in the midst of rising ethnic tensions makes the issue particularly volatile.
In Moldova's breakaway Dniester region, Russian and Ukrainian insurgents are battling the country's Moldovan majority in an armed insurrection out of fear that it will reunite with neighboring Romania. In the Georgian province of Southern Ossetia, secessionists are seeking to break away and join their kinsmen in neighboring Russia.
Russia's security no longer depends on the balance of power with the United States, Germany or other Western states but on relations with its closest neighbors, almost all former Soviet republics determined to establish their political independence from Moscow but clearly still within its sphere of influence on many questions.
With more than 40 million Russians outside the country's borders in other republics of the former Soviet Union, the Yeltsin government believes that, for political reasons, it must come to their defense. To fail to do so would put into question its own political legitimacy as a nationalist regime, and its critics are waiting to tear it apart on this and other issues.