SECRETARY OF State Muskie seems to have made a good personal impression in Europe, but otherwise his trip was as somber a trans-Atlantic mission as anyone can recall since John Kennedy met Nikita Khrushchev at Vienna in 1961. To be sure, the same smell of an impending Soviet-American confrontation is not in the air. But from Mr. Muskie's meetings with Soviet Foreign Minister Gromyko there arose an unmistakable sense of grinding impasse. Furthermore, there is a deep and painful strain between the United States and its allies. This was not so in 1961.

To Mr. Gromyko, Mr. Muskie evidently said in private what he had said publicly he would: that Soviet readiness to withdraw from Afghanistan is the key to any effort to build mutual understandings on other issues. The Kremlin is not likely to bow to such bluntness. But for Mr. Muskie to have started down the road -- a sigh, a shrug, tacit acceptance of the invasion as a fait accompli -- that some Europeans and even some Moslems have begun to tread would have been a political and moral disaster. There is no denying that this leaves Soviet-American relations across the board in a sour and unpromising state. The impending succession crisis in Moscow and the presidential elections in the United States make it unlikely that either side will have a major policy review, or a mandate for a new policy, at least until next year.

The allies keep demanding that the United States show leadership. When Washington does, the allies -- the French more, the Germans less -- point out the undeniably real flaws in the president's (any president's) tactics or personal style and use that as a pretext to avoid sharing the full burdens of alliance partnership. In Naples yesterday, various of the European nine could be seen slipping off their month-old pledge to clamp tough sanctions on Iran. Earlier in the week, the allies could find no common response to the new Soviet offer to start withdrawing from Afghanistan if, in effect, others accept and guarantee the pro-Soviet regime. Mr. Muskie acknowledged that the Europeans had not been dissuaded from moving toward their own Mideast approach, one that will undercut Camp David. French President Giscard d'Estaing's suddenly sprung visit to Poland to meet the Soviet leader, Leonid Brezhnev, is only the most conspicuous sign of the European readiness to break alliance ranks.

This is the fourth year of an administration in trouble on many fronts. It was foolish to imagine, if anyone did, that a change of face at the State Department could check the slide in American foreign policy. Mr. Muskie came aboard less to start off on a new tack than to supply some steadiness and judgment. But had they chosen, the Soviets could have made a gesture to the new secretary -- pulling back a division, for instance. Even more easily the Europeans could have used the occasion of his baptismal trip to convey the sense of a fresh start in a time of crisis. This did not happen. It leaves the administration obliged to read water warily, to deal with daily difficulties in a steady way and to avoid making things worse than they are.