If you could take a snapshot of European political attitudes this summer, the photograph would be dominated by a threatening horizon -- dark, but vague. Over here things don't look so good, particularly on that horizon.

"The horizon" begins in September; Europeans have become so civilized that they refuse to let important events occur in July or (especially) August. September will mark the beginning of what the Germans are calling "ein heisser Herbst" -- a hot autumn. It is likely to be nasty, perhaps even ominous.

The Germans are worried about the prolonged protests they expect against the deployment of new American missiles, scheduled to begin in December. Some German politicians say with grim certitude that people will probably die in these protests, which many expect to be the biggest and most violent in West German history.

This is not the only source of European anxiety about the months ahead. The weeks since Margaret Thatcher's reelection have been filled with news of thousands of new layoffs by British industries, and Thatcher has announced a "program" for her new government which, on the central issue of unemployment and recovery, contains nothing new. Many Britons remain impressed with their prime minister because she is "a leader." But when asked where she is leading, even her fans aren't sure.

In France there is a palpable malaise in the summer air -- nothing vague or amorphous like Jimmy Carter's American malaise of 1979, but a very explicit disappointment with the socialist government, its leaders and policies in a society that is much more political than America will ever be. In Paris everyone seems to be complaining about Francois Mitterrand, not only because the franc has tumbled in value while recession has taken hold of the economy, but also because the Mitterrand government has proved to be so clumsy. Here Jimmy Carter is a good comparison. By all accounts, Mitterrand has matched Carter's standard for political ineptitude.

Now Italy has elected a new parliament that is even more fragmented than usual. The result will be a weaker Italian government at a time when Italian inflation is running at 16 percent a year.

It's not surprising that weak governments and bad economies have lead to political gloom; this has happened before. If this year's European crisis is more serious than previous versions -- and it probably is -- the reason is NATO's deployment of new American missiles.

The Reagan administration is understandably pleased that the NATO decision to deploy new missiles -- taken in 1979 in response to a dramatic buildup of Soviet missiles aimed at Western Europe -- now appears likely to be implemented. If irate citizens in Western Europe had forced their goverments to abandon the 1979 decision, the resulting loss of face for NATO and the United States would have been humiliating, and no doubt would have given great heart to the Russians.

But there is no joy in Europe that deployment of the missiles will actually start in December. The best that Europeans can say for the deployment is that -- if only for symbolic reasons -- it is better than the alternative (no deployment), though many would dispute even that.

The disconcerting fact is that almost no one in Europe is going to feel more secure even if all 572 new Pershing II ballistic missiles and jet-propelled cruise missiles are installed around Western Europe. On the contrary, the controversy provoked by these new NATO missiles has apparently made millions of Europeans feel much less secure.

The Germans have, for the first time, faced up to the fact that they are the world's most likely nuclear battleground, and that their territory (like East Germany's) is already loaded with nuclear weapons. In almost all of Europe, and especially in Northern Europe, ordinary citizens have become more concerned about nuclear weapons because of the flap over the new NATO missiles.

A senior German diplomat recently pointed out why these missiles have caused such turmoil. They represent the first time in NATO's history that the Europeans have agreed collectively on an important new deployment of nuclear weapons. Until now Europeans happily left such decisions entirely to the United States. Sharing the responsibility now has not been an enjoyable experience.

It has been made even less comfortable by the Reagan administration, which continues to play badly in Europe. Of course no American administration since John F. Kennedy's has been really popular on this side of the Atlantic, but Reagan -- like Carter -- is the sort of American that is least understood in Europe, where movie stars (and peanut farmers) simply do not become national leaders.

"It is a recordable fact that the Reaganites hold alarmingly simplistic beliefs that divide the world into goodies and baddies," a conservative British editor said the other day. It seems hard to be a sophisticated European and also an admirer of Ronald Reagan.

The Europeans also resent the fact that the Americans have fallen into spats among themselves about the nuclear issues on which they used to maintain a strong national consensus. American fights over MX missiles and nuclear freezes help persuade a lot of Europeans that "the United States can't get its act together," as one German put it -- an unnerving situation for Europeans who long ago signed over to Washington principal responsibility for their strategic defense.

There's the rub. Historians -- if there are any -- will look back with some puzzlement at the 1945-85 period, when the governments of some of the strongest, most important nations in the world largely abdicated their traditional responsibility for self-protection to another nation more than 3,000 miles away. Of course there were good historical reasons for this abdication, and good selfish reasons too, but still it has been an historic anomaly, created by thermonuclear weapons.

That epoch now seems to be ending, though some of its features will endure, and the Europeans are unlikely ever to assume total responsibility for a continental balance of power with the Soviet Union. But if Americans are to go on electing presidents who make Europeans uncomfortable, we can expect Europeans to drift further away from the traditional NATO arrangements.

Just now there are governments all over Europe whose domestic political fate may be tied to policies devised in Washington that those same governments would never adopt as their own. As we're about to learn from his trip to Moscow, Germany's Chancellor Helmut Kohl is considerably more interested in preserving some detente with the Russians than is the Reagan administration. Other Europeans are also eager to pursue normal relations across the Iron Curtain -- not just to pay lip service, but to pursue a better East-West climate.

As a wise retired British diplomat put it the other day, European voters know intuitively that the West has let the relationship with Moscow deteriorate too far. "People know how to deal with a nasty neighbor," he said -- not by provoking him, but by dealing with him realistically. And in Europe the Russians really are neighbors -- a fact of life here that many Americans don't appreciate.

Up to now the basic European tactic has been to put the Reagan administration's policies in the best possible light -- a tactic made easier by the administration's willingness to bow to European pressure to at least appear to be conducting serious arms control negotiations. This tactic may suffice for some time, but it may also collapse if Washington cannot convert the appearance of serious negotiations into genuine negotiations relatively soon.

Gen. de Gaulle understood the anomaly of Europe leaving its defense to America, so he took France part way out of NATO and developed an independent nuclear deterrent. Curiously, France is the one West European country whereed about n there has been no hint of a new "peace movement" in the 1980s. There must be some connection.

But not even France could protect itself if the Soviets were to attack, and the French are currently emphasizing nuclear (and therefore, presumably, unusable) weapons at the expense of conventional forces.

Not only the French are neglecting the actual defense of Europe. The British have now largely abandoned their traditional NATO naval role because they must devote so much of their fleet to the Falkland Islands (consider the strategic thinking behind that trade-off!). Simple and potentially effective steps to improve Europe's conventional defenses -- the construction of significant barriers to tanks in eastern West Germany, for instance -- are ruled out for political reasons.

So perhaps the horizon in Europe should look threatening. Which is not to say that Europe is about to fall to the Soviet Union, or that it is in danger of going "neutral." Neither is in the cards -- the Europeans know where their interests lie, and know too how to defend them, if they have to. Hence only a few Britons were drawn to the Labor Party's unilateral disarmament platform, and German voters rejected the Social Democratic Party's wavering approach to defense issues.

But it will be a rocky autumn and probably a lousy 1984 in Europe. This is what happens when governments lose control of events, and European governments have lost control of important events. They have particularly lost control over nuclear weapons, a fact that will continue to alarm public opinion and feed resurgent "peace" movements.

When NATO agreed to deploy new missiles in 1979, it also agreed to pursue arms control agreements that would make those new missiles unnecessary. At the time, the West Europeans expected the just-signed SALT II treaty to be ratified by the U.S. Senate. Nothing turned out as expected, and now the Western Alliance is forced to go ahead with a decision that it took largely for symbolic political reasons. The symbolic ploy seems to have failed; now we have a new kind of arms race in Europe which is profoundly unpopular among Europeans.

And, to repeat, no European will feel any safer. Indeed, no European will be any safer. This is what passes for progress in the nuclear age.

Robert Kaiser is an associate editor of The Washington Post.