IF THERE HAD been any doubt about the wisdom of denying an exclusive zone of occupation to Russian troops in Kosovo, the Russians themselves removed it with their secretive entry into Pristina early yesterday morning. With its misleading and confusing series of statements and counter-statements, Russia's government cast doubt on its trustworthiness as a partner. More important, with their victory rally with Serbs in Kosovo's capital, Russian soldiers demonstrated anew that their sympathies lie more with the criminal perpetrators of Serbia's war than with its victims. Those sympathies make Russia's army a poor choice to play the role of protector of returning deportees.

Russia's true intentions, and even whether it is possible to speak of the Russian government as a single actor, remain unclear. It's possible still that Russia wants to play a cooperative role; that exuberant generals, acting perhaps out of wounded pride or a misguided sense of patriotic competitiveness, simply moved out a bit ahead of schedule. It's also possible, though, that Russian officials, maybe conspiring with Serbian leader Slobodan Milosevic, want to sabotage NATO's peacekeeping -- to work toward a partition of Kosovo, to shield Serbian war criminals from investigation and arrest, to discourage the return of ethnic Albanians.

NATO and the Clinton administration are right to negotiate with the Russians in the hope that the first reading is accurate while doing everything possible to hedge against the second. That means, above all, deploying NATO's 50,000 peacekeepers as quickly as possible to make clear that Russia's few hundred cannot shape the peace. Negotiations, meanwhile, look for an arrangement that would keep Russia engaged in this process -- still a worthwhile goal -- without letting it play wrecker. That means Russia can't have its own zone, and a NATO general must have sole command of the overall force.

Beneath these uncertainties lies the familiar question of who, if anyone, is in charge in Moscow. Russia's foreign minister assured the White House Friday night that Russian troops wouldn't enter Kosovo; in they went. Russia's government called the deployment a mistake; then President Boris Yeltsin claimed credit for it. Was Mr. Yeltsin playing a double game all along, or was he yesterday just trying to put the best face on his inability to control the military? For a vast, unstable nation with a vast nuclear arsenal, neither possibility is comforting.