The fear spreads that the Western alliance is slipping into a period of unprecedented peril, with the Soviet Union poised for a great geopolitical leap forward that will leave Europe, and to a considerable if lesser extent the United States, "Finlandized," quivering under the paw of the Soviet bear. Henry Kissinger says so and many harken.

But some don't harken, and deserving first rank among them is Helmut Schmidt, West Germany's chancellor. To me he is far and away the most impressive politician around, with proven competence in democratic governance and a wide-angled view of the future. As a German, a former defense minister and a centrist who does not wear the left's rose-colored glasses, he lives with the awareness that his country would be the first and biggest victim of an East-West breakdown. Yet he stays sober and balanced on his side of the Atlantic while a fevered apocalyptic view gains currency on the other.

He now says, in The Economist, that while there is a Soviet buildup, there is "no need for alarm" -- as long as the West is not "negligent" and maintains military "equilibrium" at all levels. The current Kremlin leadership, he thinks, wants stability, not adventure, though "the Russians always want to be on the safe side, having a little more . . . Therefore the West has to respond, to tell them that this is being overdone."

He finds the German situation -- he means, openly, both German states -- more secure than in past decades: a military equilibrium stabilized by political agreements that have made West Germany's Ostpolitik a far greater practical success (Berlin, trade, emigration, etc.) than East-West detente overall.

Politics being politics and Germans being Germans, not everyone will agree. These are, however, the judgments of a tested leader and, beyond that, of an economically, politically and militarily strong country on the front line.We Americans, in the rear, accustomed to having our judgments of the common peril accepted by the allies without dissent, might consider that it is a bit odd to be more alarmed, and more alarmist, than the Germans. They are the canary in the coal mine.

Events have just brought to center stage an old Schmidt concern -- the middle-range nuclear weapons that Russia has ready to fire at Europe but Europe does not yet have ready to fire at Russia. Schmidt has long warned that the superpowers' approach to parity would aggravate Europe's strategic cares, preventing it from evading further the question of whether in a crisis the United States would risk, say, Chicago for Bremen. Schmidt's answer is for Germany to host the new middle-range American missiles that could reach Russia; he reaffirmed this the other day after Leonid Brezhnev ordered him to back off. NATO is moving his way.

In fact, Schmidt is moving NATO his way. American diplomacy has worked -- sometimes effectively, sometimes noisily, erratically, patronizingly -- to put the choice to the Europeans, but Schmidt has taken the crucial European leadership role. Supported by his friend French President Valery Giscard d'Estaing, he has filled what Europeans have come to see as the partial vacuum in alliance direction created by Jimmy Carter's travails.

Schmidt (with Giscard) has won acceptance and legitimacy in Europe for the idea that Europe must face up to the special requirements of its post-SALT II defense, nuclear and conventional. He has made of the program to put the new missiles in Europe a vehicle for strengthening alliance cooperation across the Atlantic and within Europe too. Most important, he has shown a typically edgy and divided domestic European public the way to keep up defenses without sacrificing what are for Germany the immense benefits of detente in terms of trade, the movement of people and the lowering of tensions. Not for him simply to add up raw numbers and bow to politically disembodied military "trends."

True, I am running ahead of the story. The matter of the missiles is, at best, months away from completion. Schmidt insists, entirely reasonably, that Germany should not be the only non-nuclear European country to host the new missiles; this poses a tricky who-else problem. If Carter fails to carry SALT II, the whole European plan could collapse since Schmidt, again entirely reasonably, has linked hosting the new missiles to putting them and the Soviet missiles they match on the table in SALT III.

Schmidt conveys the feeling, nonetheless, that he can do what he has to do. It does not make light of his burden to observe that he looks at it with an unblinking eye, without panic.