PUT DOWN Tuesday, June 12, as the day Mikhail Gorbachev took two very large steps to clear a path to the economic renewal that is increasingly his first priority. He made the concession that may make possible an eventual working out of the Lithuania crisis. And he moved close to accepting the rapidly emerging reality of a united Germany's membership in NATO. The movement on these towering issues is all the more striking for the fact that just 10 days ago, at the Washington summit, they had seemed caught up in a tight Kremlin stalemate.

Receiving the elected heads of the three Baltic republics, Mr. Gorbachev stopped insisting that they cancel their declarations of independence as a condition for opening negotiations on independence terms. It is enough, he said, just to suspend the laws they have enacted since those declarations. He went on to speak broadly of a new treaty or form of association among the republics offering them sovereignty and separately tailored links with the center.

This hint of breakthrough followed, among other things, the election of Boris Yeltsin to the Russian republic presidency and that huge republic's own reach for sovereignty. Mr. Gorbachev must now deal not just with a special case in the Baltics but with ethnic assertion throughout the country, heartland included -- and with a major political challenger as well. Lithuania remains in the grip of a Soviet economic stranglehold. The difficulties of constructing a new federation cannot be exaggerated. But the Baltic crisis may be easing.

On Germany, President Gorbachev seems now to be preparing his parliament and public for the imminent possibility of a Germany united and firmly embedded in the Western Alliance. He is still toying with the idea of Germany's becoming an ''associate member'' of both NATO and the Warsaw Pact. But the West rightly insists that Germany be a first-class citizen in NATO, which is an organization in transition but a living one, and even Mr. Gorbachev no longer asks that East Germany remain in whatever may soon be left of the disappearing Warsaw Pact military structure.

It falls to the West to ensure that the Soviet Union, as it absorbs the political shock of allowing its allies choice and thereby losing its alliance, does not also suffer material loss to its security. Perhaps later something will come of the new pan-European security structure of which Mr. Gorbachev plaintively speaks. Meanwhile it is important to make the single existing structure, NATO, useful to the whole continent's evolving security needs.

To soften policy toward both Lithuania and Germany -- on the very day, by the way, on which the Soviet parliament approved an untested but promising law establishing freedom of the press -- can yet help President Gorbachev in his desperate reach for Western economic support. A relaxation in Lithuania had become an explicit condition for congressional approval of a full-fledged American-Soviet trade agreement. The Soviet Union could not hope to enlist the resources of Germany, the country most fit and ready to take part in its economic development, without offering Germany and its allies reasonable satisfaction on the specifics of healing the Cold War division of Europe.

Much remains to be done on both these issues to bring the expected foreign benefits to the Soviet Union, which cannot hope to put them to good use without far deeper economic reforms at home. The policy changes Mr. Gorbachev is now steering into place, however, are crucial to his prospects for success.