THE warnings and counter-warnings flying between Vilnius and Moscow should be the precursors of serious negotiations about Lithuania's separation from the Soviet Union - not the forerunners of open conflict. The tiny republic is resolutely standing by the principle that it never willingly gave up its independence, and therefore has a right to reclaim it. In this view, the first freely elected Lithuanian parliament in 40 years simply did what its constituents demanded: declared freedom from an occupying power. This was people power in its purest form.
But that other kind of power still exists. It was evident in the jets that buzzed Vilnius, in the troops that suddenly went on maneuver, and in Mikhail Gorbachev's decree that Lithuanians turn in their weapons.
Much is at stake here. First, Lithuania's bold gamble that it can wrest its freedom back at a time of turmoil and change in Soviet society. Second, the endurance of a Soviet political union based on past conquest and police-state authority. Third, the international reputation of a Soviet leader honored abroad as a courageous reformer but under increasing pressures at home.
Without question, Lithuania deserves its independence. The method by which it became part of the Soviet Union - a pact between two vicious dictators - has no validity. The task is how to find a politically practical way of achieving independence. Lithuania's new, non-communist government has chosen the most direct route, forcing an issue that Moscow would like to draw out indefinitely. The secession legislation being hammered together by the Soviet parliament expresses that preference.
Lithuania's frontal approach to independence is clearing the way for neighboring Baltic states, Latvia and Estonia. Nationalists in other parts of the Soviet Union are watching too. Mr. Gorbachev wants to demonstrate that secession is a drawn-out, painful process about which reasonable people should think twice.
It's not likely, however, that Mr. Gorbachev is going to get the Lithuanians to think twice. His options boil down, ultimately, to letting the republic go or militarily occupying it. The latter would only prove the Lithuanians' point about their forced ``membership'' in the union. It would also damage Gorbachev's image abroad, threaten arms treaties, and deepen Soviet internal turmoil - just as far-reaching economic reforms are starting up.