Reagan administration policies have until now essentially pursued familiar American strategies and alliances - it has mainly been a case of ''more'' and ''better'' rather than conceptual innovation. In particular, the administration's defense planning has proceeded from established United States commitments to the defense of Europe combined with jawboning for increased contributions from the allies. But among the President's supporters are some whose conservatism challenges these very commitments that have characterized American security policy for more than 30 years.
Laurence Beilenson, whom the President calls his ''good friend,'' is clearly one who does not accept the post-World War II precepts of American foreign and defense policy. He advocates a nuclear fortress America concept, suggesting that the US maximize its nuclear offense and defense while withdrawing most conventional American forces from overseas commitments. Such views occur in ''Survival and Peace in the Nuclear Age,'' a book for which President Reagan commended the author when addressing West Point graduates earlier this year.
All of this would be of little interest under different circumstances. The NATO alliance has survived many bumpy periods, radical proposals, and dire predictions. But today the alliance has clearly entered a new crisis, characterized by deep policy differences between the US and Europe. The crisis is intensified by the fact that the US, seeking to reassert its leadership of the Western world, now faces allies which still need the defense guarantee provided by the US but whose political and economic maturity has given them the confidence to challenge the wisdom of American policies.
Rhetorical excesses in the trans-Atlantic dialogue have recently driven mutual misperceptions to levels unequaled since Vietnam. European reactions to President Reagan's references to the prospect of limited nuclear war in Europe illustrate the degree of European suspicion about American intentions. In this climate, it is crucial - if the political viablility of NATO remains a vital American interest - that official spokesmen choose their words and policies carefully. It is an important question, therefore, how carefully President Reagan chose his words in his West Point address.
The ideas commended by President Reagan as ''thought provoking'' would, if implemented, turn America's defense posture on its head. Beilenson maintains: ''By our far-flung military presence we have put all our eggs in the basket of deterrence. . . . In addition to overburdening the fortitude of the American people, we are preparing for the wrong war in the wrong way. . . . Defense against nuclear war and invasion of the United States should come first.'' Beilenson judges that ''for every one-seventh decrease in our conventional defense budget, we can double our nuclear budget without spending one additional dollar.''
Our most expensive overseas commitment is to the defense of Europe. Under Beilenson's plan, the US would tell the NATO allies that all American forces would be withdrawn from Western Europe in equal installments over a five-year period.
What if the Soviet Union were subsequently to conquer Western Europe? According to Beilenson, we shouldn't worry: ''A conquered Europe would inflict upon the Soviet Union a fatal case of acute indigestion.''
Beilenson does not, however, want to leave our European allies totally helpless. The nuclear umbrella would remain extended over Europe for a period of time while - and this is the heart of the solution - West Germany is given the necessary technical assistance to become a nuclear power alongside France and the United Kingdom.
What if West Germany did not want to become a nuclear power? No problem, according to Beilenson: ''We should leave our allies no room to doubt that if the proposal is rejected, our men will be brought home and our nuclear protection withdrawn. Faced with that alternative, the West Germans in the front line would have little choice.''
Would West Germany and other European countries become subservient to the Soviet Union (''Finlandized'') rather than build the requisite conventional and nuclear forces to substitute for the US defense guarantees? No matter, says Beilenson, ''The loss (of our pro-Western allies) would be more than offset by our increase in nuclear arms from the money saved by bringing home our conventional forces and disbanding them.''
Previous postwar attempts to reduce the American presence in Europe have been led by political liberals (former Sen. Mike Mansfield, for example). Those efforts have traditionally been thwarted by a coalition of centrist and conservative officials in the executive branch and in the Congress. The President's praise for Beilenson suggests that there is at least an outside chance that a neo-isolationist alliance between conservative and liberal political forces in the US could revolutionize America's future approach to its alliances.
Could President Reagan, exasperated by European unwillingness to accept his threat perceptions and his administration's prescriptions for Western security, eventually reject the deep US commitment to European security? So far, the administration's actions have included no hints of such a radical departure. There are high costs associated with our current defense posture and commitments and frustrating inequities in relationships with our major allies. But discarding a system which has preserved East-West peace while ensuring a high degree of internal Western political stability and economic strength entails risks that no previous President has found advisable to take.