In Washington, a new U.S. weapon now under development is called the "GLCM" which in Pentagonese stands for "ground-launched cruise missile."

In Western Europe, that same abbreviation is jokingly referred to in some quarters these days as meaning "German-launched cruise missile."

In Moscow, the joke undoubtedly is not amusing.

The prospect that someday hundreds, or perhaps even thousands of these small, jet-powered cruise missiles - able to fly hundreds or perhaps more than 1,000 miles - may be based in West Germany is a major concern of the Soviet Union.

For the first time, Weapons based in West Germany and possibly under West German control - if they are armed with conventional warheads and not with U.S.-controlled nuclear warheads - will be capable of reaching targets not only deep inside Eastern Europe but in the Soviet Union itself.

The Western allies for years have had long-range jet fighter-bombers such as the F4 Phantom based in West Germany that theoretically could reach Soviet targets but with only a slim chance of getting back to fight again. Those planes, and others like them, were not designed for such missions. They are for use in repeated flights along and just behind the front lines of a Central European battlefield.

So it is the cruise missile that potentially would give West Germany weapons to hold the Soviet Union directly at some risk in any attack.

This is a side issue in the overall U.S.-Soviet efforts to negotiate a second strategic arms limitations treaty (SALT) to replace the one that espired in 1977.

The major Soviet concern is to limit U.S.-deployment of air and ground-launched cruise missiles, since they could help the West equalize a substantial Communist bloc advantages in tanks, artillery and manpower along the front.

Given the history of Europe this century, the question of missiles is Germany has an added East-West dimension.

If Carter administration predictions are accurate, a Salt II agreement can be initialed soon by U.S. and Soviet leaders. A start on the follow-on Salt III could come within the following six months, in the view of officials at the North Atlantic Treaty Organization here.

SALT III is meant to deal with a variety of sticky questions that for the first time, probably will involve weapons based in Europe and European political interests, rather than be concerned solely as in the past with the U.S. Soviet nuclear balance of power.

Yet experienced officials here say that, as one of them put it, the West Europeans "are absolutely nowhere in terms of preparation on either the procedure or the substance," of what they really would like to see happen in the SALT III discussions.

The cruise missile is just one, but not the only example. A build-up of such controversial weapons on West German soil could touch off a hugh political debate in Bonn.

Chancellor Helmut Schmidt, though a supporter of strong defense, would come under heavy pressure from the left wing of his Social Democratic Party, which undoubtedly would argue that a build-up of these missiles here would, in fact, guarantee turning West Germany into a battlefield if war comes.

There is also pressure, from the conservatives in Bonn, in the other direction. The result is that the West Germans have not really decided what they think about these weapons.

Similarily, it is not clear what, if anything, the West can do to force Soviet restraint in building new SS20 intermediate -range missiles and Backfire bombers that are targeted on Western Europe.

While the West Germans are urging the United States to try to control these weapons through the SALT negotiations, strategic planners here see a danger in the West trading restraint of such warplanes as the European-based Phantoms for Soviet restraint in another area.

They argue that the U.S. jets are meant to offset their counterparts its the Soviet Air Force and in Soviet front-line Army strength and that if they are used as bargaining chips against longer-range missiles and bombers, the West will sacrific real capabilities.

The U.S.-developed neutron warhead for short-range missiles and artillery is another potential weapon that may enter into new arms control discussions.

Like the cruise missile, the neutron weapons are not being mass produced and may never be. They are commonly portrayed as counters to the heavy Warsaw pact advantage in ground forces. But military strategists also see them as forcing the Soviets to spend more on defensive, rather than offensive, systems.