Unexpected events determined that Secretary of State Cyrus Vance would go to the Middle East this weekend, while Deputy Secretary Warren Christopher filled in for him at the NATO council meeting in Brussels. But the result delivers a message of importance to the world.

The Atlantic alliance is not, as the cliche has it, a beleaguered pact reeling under Soviet pressure. On the contrary, the European political leaders are in very good shape, their ties with the United States are exellent, and economic pronlems are far more serious than the security threat posed by the Soviet Union to Western Europe.

Some chronic problems persist, to be sure-enmity between Greece and Turkey, the Italian Communists, unrest in the Iberian peninsula and yearnings for Tolstoyan peace in parts of northern Europe. These troubles, however, are like rheumatism-painful but not fatal.

In contrast, there are the favorable political developments at the heart of the alliance. In Westr Germany, Chancellor Helmut Schmidt has turned a crucial corner by surviving the state election in Hesse on Oct. 8. The Christian Democratic opposition has buried hopes of unseating the Social Democratic governm,ent before the next election, and Schmidt's coalition partners, the Free Democrats, have abandoned thoughts of a bolt. The chancellor is safely in the saddle until 1980, and has a good chance of reelection and a hold on office until 1984.

in France, the seven-year presidential term of Valery Giscard d'Estaing does not expire until 1981. In the March elections this year, he turned a corner in beating back a challenge for a majority in the parliament by a left-wing coalition of Socialists and Communists. The leader of the Gaullists, Mayor Jacques Chirac of Paris, has lurched so far to the right that it is hard to see how he can ever command a majority of the French popular vote.

British Prime Minister James Callaghan enjoys no great majority in the Commons. But he has resisted the challenge posed by the Tories to his economic policy at the beginning of the current parliamentary term. He is secure until he calls electionnext year, and he looks to be on the right side of the inflationary issue.

With their own political hides secure, the Europeans have been far less prone to blame everything that goes wrong on the Americans. For example, Egon Bahr, once one of the most virulent critics of the Carter administration, came to town the other day for a lecture at Georgetown University. He seized the occasion to make it plain that at long last the Europeans have come to understand President Carter and his men.

One reason for the good feeling about the United States is that joint efforts are paying off. The military modernization program is giving the NATO ground forces the kind of readiness, reinforcement capability and anti-tank defense they need to make even more unlikely the extremely unlikely event of an over-the-top assault by Russian troops. That is one reason why it is right for President Carter, despite the anti-inflation program, to sustain the commitment the United States made in return for a similar commitment by the other allies for a 3 percent real increase in defense spending next year.

The deterrent power is all the more formidable given developments on the other side of the hill. The latest shift in the Soviet leadership-the inclusion of a 67-year-old apparatchik in the Politburo-faithfully expresses the dynamism of the regime of Leonid Brezhnev. The refusal of Romania to go along with increased contributions to the Warsaw Pact is a reminder to Moscow that East German, Czech and Hungarian forces in the pact would not necessarily fight for the Russians in a showdown.

To be sure, financial problems-notably the weakness of the dollalr-remain. But the Carter administration has now followed European wishes in making inflation public enemy No. 1 and in moving tosupport the dollar. It has welcomed the European Monetary Union.

So, the administration has grounds for asking the Europeans to await patiently the results of the anti-inflation effort, and to participate wholeheartedly in the negotiations for reaching a new multinational trade agreement by the end of this year. It might even be appropriate for Washington toremind France that the imprecations hurled daily against the shah of Iran by the exiled Ayatollah Khomeini from Paris do not exactly help a Western world dependent for oil upon Iran and its neighbors.

The fact is, as Vance confides to visitors, that European security concerns are essentially over. With defense ensured, there is room for plain speaking on econmic matters and no need to tolerate prima donnas.