The view through the 'window of vulnerability'

Let it be noted that today, all Americans, along with their friends and allies around the world, are sitting right in the middle of that ''window of vulnerability'' to Soviet missiles that we were told would be so desperately dangerous. Relative Soviet power is, or is supposed to be, at an all-time peak.

Just how dangerous is it, really?

Talk to the diplomats and you get varying reactions.

One Soviet Embassy official in Washington has been quoted anonymously as saying that ''East-West relations are at their lowest point in history.'' American State Department people tend to be less excited. One West European diplomat remarked:

''People who talk about this being a second cold war simply don't remember what the real cold war was like.''

He went on to reminisce about the sense of tension that prevailed in 1948-49 when the Soviets blockaded West Berlin and the Allies responded with the greatest airlift in all history. There was indeed tension in the air in those days and many a sleepless night for those responsible for trying to manage the crisis without setting off a third world war.

There was even deeper anxiety in 1962 when American reconnaissance planes broke through the clouds over Cuba and obtained detailed photographs showing Soviet nuclear missiles in the process of being deployed.

Those were intermediate-range missiles which, from Cuban bases, could reach targets in the central areas of the United States - areas that were previously protected from surprise attack by the DEW Line. That was a Distant Early Warning system that covered North America from anything coming over the North Pole. But the DEW Line did not exist for something coming from the south. If those missiles in Cuba became operational the Soviets would have outflanked the existing early warning system.

My Western diplomat remarked that in those days, as he was working at the foreign office on the latest cables, he more than once almost picked up the telephone to tell his wife to take the children and head for the farthest place they could reach from the capital. Those were truly tense days.

There is East-West tension in the air now, yes. President Reagan keeps referring to the Soviets in critical terms. George Shultz, the new US Secretary of State, has had two recent meetings with Soviet Foreign Minister Andrei Gromyko - and achieved nothing except to identify the areas of disagreement. There is simply no opportunity at the moment for the US and USSR to do constructive business together.

The only thing the two foreign ministers could do was to talk together in civil tones. A dialogue is still possible, although the dialogue is the end of the matter. The Soviets have no intention at present of pulling their troops out of Afghanistan or of allowing the Polish people their freedom. So long as those conditions prevail, Washington would be unable to talk about improving trade between the two.

Besides, were President Reagan to propose business with the men of the Kremlin, he would thereby undercut his own program at home for building up US military power. His arms program rests on the thesis of the implacable hostility of the Soviets toward the US.

So there is virtually no diplomatic traffic between Washington and Moscow. And yet this is the time of the window of vulnerability. The Soviets have more warheads targeted at the US than ever before. In theory, as preached by ''hawks'' of the American military establishment, this is the time when their extra-heavy missiles could knock out most of the land-based Minuteman missiles in the US and then be able to destroy most, if not all, American cities.

These are the days President Reagan wanted us to prepare against by emergency defense spending. These are the days when the Soviets in theory can make demands on us and threaten us with their allegedly superior nuclear ''throw weight.''

But where is the pressure on the West from the Kremlin? Where is the brandishing of Soviet weaponry? What new wickedness are the Soviets performing, or plotting?

Perhaps something alarming will happen tomorrow.

But the diplomats of the West, whose ears are supposed to be acutely sensitive to pressures and dangers, do not sense special tension or unusual danger. They know of no reason to think that the Soviets intend to try to take advantage of a superiority that after all may exist more in Washington fears than in Soviet conviction.

Is it all to be explained by a misunderstanding of the world situation? Are the Soviets less strong than President Reagan thought they were when he came to Washington?

Or are they so preoccupied with their own internal and domestic problems, and so stretched by trying to hang on in Afghanistan and to keep Poland from escaping from their clutches, that they can do little more?

Some Western experts try to explain it just by the uncertainty about how much longer Leonid Brezhnev will be running the show in Moscow. Some think that American hawks have exaggerated both the window of vulnerability and the eagerness of the Soviets to do harm in the West.

Others think there are men in the Kremlin who think that the Soviet Union can gain more influence in the world by being quiet, restrained, and nonbelligerent than they could by brandishing their weapons.

Take your choice of explanations. No one on the outside can be sure what considerations and arguments carry the most weight inside the room where the Soviet Politburo sits at moments of decision. All those of us on the outside can know is that the Soviets are probably stronger right now in military power than they ever were before, and stronger than they are likely to be in the time ahead when the latest American weapons will be deployed.

The new weapons are coming along. The new Trident submarines are coming off the ways in Connecticut. The MX missiles are being planned for deployment - if and when Washington can agree on how to deploy them. The new Pershing missiles are being planned for deployment in Europe if and when the Europeans can agree on taking them.

The window of vulnerability is going to be closed shortly. This therefore is probably the last best chance the Soviets will have for a long time to flex their military muscle at the US. So far, they seem to be relatively quiescent - almost as though they themselves do not believe that they're actually superior in weapons.