YET AGAIN a tough nuclear deployment issue strains the Western alliance. It arises directly from NATO's achievement the last time around in making the deployments that produced the INF Treaty. This time the weapons at issue are short-range and battlefield nuclear forces with ranges under those of the classes the INF Treaty bans. NATO, in the cold days of 1983 when an INF treaty was hardly even a fantasy, had decided to modernize the 88 short-range Lance missiles. The matter was set aside during the INF sequence, but now it's back. There is a widespread feeling among NATO officials that it's more important than ever to strengthen these arsenals in view of what will be eliminated by treaty accord.

Except among the Germans. They are painfully aware that, alone among classes of nuclear weapons, those of short range are based and would be used mostly on German soil. This consideration, not surprisingly, induces a nationalistic hesitation on the German right and stirs antinuclear inclinations already strong on the German left. The other allies are getting a bit anxious and defining the issue as a large test of alliance fidelity and the credibility of deterrence. The Germans, resisting isolation, are playing for time in order to find an acceptable two-track formula of modernization and negotiation.

What NATO has here is no more or less than the latest Kremlin effort to frazzle the West. This is the Great Game of the postwar period, and Mikhail Gorbachev, far from ending it, is using his image, momentum and skill to engage in it with new vigor. The challenge he is mounting builds on denuclearization, a glimmering but imprudent goal that Ronald Reagan embraced at Reykjavik. Mr. Gorbachev is asking Europe to move toward denuclearization in the matter of short-range and battlefield nuclear weapons. As an alliance, NATO is resisting on grounds that it would be rash and dangerous to go that way before addressing vital issues of strategic and conventional arms. In Germany, nonetheless, some citizens are tempted.

It does no good -- it does harm -- to give undue life to the suspicion that the Germans are going to default on their alliance obligations. Better to count on them to come in their own way -- as they always have in NATO's 40 years -- to the support of agreed alliance goals.