NATO is facing the need to make some serious but smooth adjustments if the alliance is to continue its 33-year history of deterring war in Europe.
West German government officials, military officers, and scholars see this, rather than any immediate ''crisis,'' as the main challenge confronting the alliance as it goes through a period of subtle change. As seen from here, the Americans will have to adjust to the following:
* That the European allies' share of the cost of a common defense is not going to greatly increase. It is unrealistic for the Reagan administration to expect large increases in defense spending here, West German officials say, given current economic difficulties and the large contribution already made by the Federal Republic.
* That there will continue to be steadily improving contacts between East and West Germans. These should not be misunderstood by Americans, say West German officials, since they are significant for the lessening of broader East-West tensions.
* That improvements are now taking place in French-German military relations. These can only make NATO stronger, officials here say, and ought to be encouraged.
* That any shift from deterrence based on nuclear weapons toward a new US plan for countering attacks more aggressively with conventional weapons may heighten public concern about war. Hence, any such shift will have to be approached carefully, officials here say.
The alliance's military chief, US Army Gen. Bernard Rogers, said recently that the European allies should increase their defense spending just as the Reagan administration is doing for the US. Some US lawmakers base their calls for a reduction of American troop strength in Europe based largely on this question of ''burden sharing.''
Europeans in NATO counter that they steadily increased such spending through the 1970s while the US fell behind. They remind Americans that they maintain more cost-effective conscript forces and provide valuable real estate for facilities that bolster US security.
While acknowledging that ''Europe must grow stronger in order to relieve the United States,'' conservative West German parliamentarian Peter von der Heidt recently told visiting American journalists he doubts that General Rogers' goal of a 4 percent per year real increase can or should be met.
Polls consistently show that 70 to 80 percent of all West Germans view the US favorably and want to remain part of a strong NATO that includes the 233,000 American service personnel on their soil. At the same time, with more than 90 Warsaw Pact divisions not far from the inter-German border and 4,000 potentially hostile aircraft no more than 10 minutes away, West Germans have a decidedly different view of East-West relations.
''I would not say that we're turning away from the alliance, but that we're just growing up,'' says Mr. Von der Heidt, a Christian Democrat and member of the West German parliament's Foreign Relations Committee.
More than their American counterparts, West German military specialists give greater weight to the defense capabilities of France and the likely role it would play in case of attack, notwithstanding its independence from the NATO military structure. France keeps 51,000 troops on West German soil. Leaders from the two countries met recently to discuss mutual defense interests, including France's new emphasis on its own nuclear forces.
''France is much more integrated into NATO than it looks on the surface,'' says Wilfried Hofmann, head of the NATO desk in the Foreign Office in Bonn.''We are satisfied that, should the need arise, the French troops would be with us from the first moment.''
For years, a major portion of allied deterrent strength has been its 6,000 battlefield nuclear weapons and longer-range theater nuclear weapons. Allied strategy has been based on the threat of using such weapons in the face of a Warsaw Pact conventional force that outweighs the West in such things as tanks and planes by 3 to 1.
NATO commander General Rogers recently has been stressing a more muscular and aggressive allied conventional capability equipped and manned to attack Warsaw Pact rear echelons and installations within Eastern Europe, should war break out.
It may have at least superficial appeal for those who are fearful of so many nuclear weapons on German soil. But it is unlikely to satisfy either the peace movement - or the German military. Rear Adm. Kurt Fischer, head of the military policy division in the West German Ministry of Defense, states flatly that ''the North Atlantic alliance can't do without nuclear weapons.''
''The so-called NATO triad - strategic, intermediate, and short-range nuclear forces - as well as conventional forces form an inseparable complex,'' says the young admiral. ''The deterrent effect of the triad is dependent on each individual component being credible by itself.''
An important part of the debate over allied military might is the issue of East-West relations among the potential battlefield countries. The Reagan administration pushes for a tougher line on such things as the Soviet gas pipeline, trade credits, and technology transfer.
But here, detente is seen more in terms of relations between Germans on either side of the East-West border. During the 1970s, the annual number of travelers from the East quadrupled to 4 million and the number of phone calls between the two Germanys jumped 30-fold to more than 23 million. Agreements have been reached on such things as pollution control and railway electrification. -Dieter Castrup, head of inter-German affairs in the Foreign Ministry, says: ''This is enough to show that detente is not an abstract term with a pejorative connotation.''