The popular wisdom in Washington is that the United States must depend on its allies in Western Europe to help achieve American goals, whether it involves a boycott of the Moscow Summer Olympics or sanctions against Iran.

For this reasosn, the Pentagon has kept tight security wraps on a potentially explosive strategy report that advocates an almost total U.S. withdrawal from Europe as a move that offers "the best prospects for the future."

What lends the report weight is its authorship by two of the Defense Department's best and brightest -- Adm. Harry Train, head of the U.s. Atlantic Command, and former deputy defense secretary Robert Ellsworth. Train's duties include command of NATO's Southern European naval strike and support forces.

The secret, 35-page report spells out the authors' recommendation that the United States drastically decrease its NATO commitments in the intersts of national security. In a nutshell, Train and Ellisworth suggest that our European allies simply cannot be depended upon.

The report is not regarded as a crackpot commentary. Pentagon sources told my associate Dale Van Atta that the report offers "very viable" alternatives to U.S. policy. How many top defense strategists share the authors' views is not known.

Train and Ellsworth acknowledge that Western Europe has top priority in U.S. defense thinking, over Asia and the Middle East. But they note the difficulties involved in this long-accepted priority.

There has been, they report, a steady "decomposition, erosion and destabilization of political will in Europe and of the European defense posture."

They say there will be "continuing congressional and public desire to cut U.S. military presence abroad," and that there exists "an unhealthy (if unavoidable) dependency by Europe on the U.S. for Europe's military security . . . (which) tends to further erode European will.

The authors of the secret report are convinced that the last-named difficulty is the most serious. They note "growing European frustration with having to pay, economically and politically, for a security guarantee from the United States."

Train and Ellsworth then argue that "a reallocation of resources and a restructured defense of NATO Europe offers the best prospects for the future." America's long-term strategy, they suggest, should aim for "an autonomous European defense and deterrent capability."

In other words, our best bet would be to force Western Europe to fend for itself, instead of depending on Uncle Sam's protective umbrella.

In terms that might irritate our European allies, the Pentagon report observes that the recommended U.S. pullout "recognizes that the Europeans today are basically irresponsible and impotent in foreign policy and security terms, (and) that their impotence is due to no small measure to their dependency on the U.S. for their military security."

The authors recommend that the United States withdraw all but a "small U.S. force" from Europe, making up for this pullout by a promise of quick military backup in the event of a Soviet attack. This would free the limited American military strength for use elsewhere in the world, encourage a credible European nuclear deterrent -- and, of course, be popular with budget-cutters at home.

The possibility that the Russians would "react aggressively" if the United States pulled out, or the Western European nations might "run to Moscow," were discounted by Train and Ellsworth as unlikely.