The United States spends more on the North Atlantic Treaty Organization than all of the 15 other NATO members combined.

This disparity was justified when this western defense alliance was formed after World War II and the U.S. was the strongest nation in the world, economically as well as militarily.But this situation has changed markedly over the past 40 years. The U.S. has become the world's biggest debtor. Nations that were once our customers are now our competitors, thanks in part to America's continued willingness to bear a disproportionate share of the burden of defending the West.

A new allocation of that burden is clearly in order. This doesn't necessarily mean that America should close some of its overseas bases and start pulling its forces out of Western Europe. Such a unilateral move could sap the strength of the arms control movement by leaving the impression that the U.S. has lost its willingness to resist Soviet aggression.

But if our allies believe that U.S. forces are essential for their defense, they should pay a bigger part of the costs associated with the deployment of American troops in Europe.

How much bigger? The answer would, of course, vary somewhat from country to country. But it will never be answered precisely as long as NATO continues to drift along without full and frank discussions of the subject.

With its new report a few days ago on NATO burden sharing, the House Armed Services Committee sent the western alliance an unmistakably strong and clear signal that ought to prompt such discussions. Insisting that Europe must eventually defend itself without a large commitment of U.S. ground forces, the committee specified which members aren't pulling their own weight in NATO.

Specifically, those countries doing "substantially less than their fair share" are Luxembourg, Canada, Denmark, Portugal, Norway, Germany, the Netherlands, Belgium, Spain, and Italy.

If the House committee erred in this listing, it was on the side of being too generous rather than too critical. Among NATO members, only Greece comes close to spending as much of its gross national product for defense as the U.S. does. Next in line, at varying distances, are Britain, Turkey, and France.

One final point: As the House committee notes, "U.S. diplomacy has failed in attaining equitable burden sharing." In dealing with some of our NATO allies, the U.S. seems to have no choice but to abandon the language of statesmanship in favor of some considerably blunter talk.