The time has come to consider cutting American military losses in NATO. It is difficult enough to justify the continued deployment in Europe of some 200,000 U.S. ground troops-- the cream of our Army--in the face of mounting pressures on the federal budget and expanding U.S. security requirements in the Persian Gulf. It is impossible to justify that deployment on behalf of rich, indolent allies that are palpably less willing to make the necessary sacrifices for their own defense than we are.

The plain fact is that our European allies are refusing to pull their military weight in the face of a comprehensive Soviet buildup that threatens NATO directly in Europe and indirectly in the Persian Gulf, a region on which our allies are far more economically dependent than is the United States. Indeed, NATO is on the verge of disintegrating as a politically cohesive instrument of collective security. Symptomatic of this disintegration are the yawning disparities in U.S. and European responses to the ongoing expansion in the very threat that sparked the birth of NATO in 1949.

In terms of per capita defense expenditure and of military outlays as a percentage of gross national product, our allies continue to spend far less than the United States. Despite a common pledge to increase defense spending annually by 3 percent over and above inflation, most of our allies have failed to do so. In contrast is the present U.S. defense program, which calls for annual real increases averaging 7 percent over the next five years.

Europe's military abdication is equally apparent in the Persian Gulf. In response to the Soviet invasion of Afghanistan and subsequent other violent threats to uninterrupted Western access to the region's oil, the United States has undertaken a costly program to establish a credible force presence in the area, while Allied leaders have contented themselves with little more than diplomatic hand-wringing and reassuring plane rides to Moscow where, paradoxically, at least in the case of German Chancellor Helmut Schmidt, contracts were signed for increased imports of Soviet oil and natural gas. NATO's impending collapse as a coherent military collectivity is most apparent, however, in the swirling controversy that has engulfed the alliance's program to place in Europe a new generation of theater nuclear missiles as a counter-weight to the Soviet Union's deployment of SS-20 missiles and Backfire bombers aimed at western Europe. The 572 new NATO missiles, the first of which are scheduled for deployment in late 1983, are to be assigned only to U.S. forces; the United States also will bear the entire cost of developing and producing the missiles, estimated at $5 billion.

Yet since 1979 key allies, subjected to pressure by Moscow and by powerful domestic constituencies that regard America as a greater threat to international peace than the Soviet Union, have backed away from the agreement they signed. Holland has more or less reneged on its pledge to accept its share of the missiles, and Belgium and Germany have attached a host of political conditions to their final acceptance that will be difficult to satisfy. The result could well be a European failure to implement a program whose implementation is widely regarded as an acid test of political cohesion within NATO.

The time has come forcefully to remind our European allies of certain political realities on this side of the Atlantic. The first is that although Europe is America's first line of defense, it is certainly not our only line of defense. The second is that the commitment of the Congress and the American public to NATO is not, and never has been, unlimited and everlasting. If Europe's political tolerance for long-overdue military measures in response to expanding Soviet military power is declining, so, too, is the American taxpayer's tolerance for guaranteeing the security of allies who continue to behave as if nothing militarily eventful or strategically consequential has happened in the world since the 1950s.

Finally, our European allies must be made to recognize that American isolationism, at least in its classic garb as resistance to security entanglements in Europe that could involve the United States in war, is not dead but only dormant.

Gentle diplomatic entreaties to our allies to do more for their own defense will no longer suffice. They must be informed in no uncertain terms that unless they pull their military weight within the alliance, they cannot expect the United States to do so. An effective means of conveying this message would be to tie U.S. ground force levels in Europe to allied military performance. An example would be a congressional act mandating the automatic withdrawal from Europe of 50,000 or 100,000 U.S. Army personnel upon the failure of Germany to deploy its full share of NATO's new missiles on schedule.

The United States has never been in a position to defend Europe by itself, nor is Europe the only area of the world where the United States possesses vital security interests. U.S. troops now allocated to the defense of allies that are unwilling to do their part can certainly be utilized elsewhere in the world.