Are Peking and Washington on a collision course over American arms sales to Taiwan? On the surface, if Washington insists on continuing to sell ''carefully selected arms of a defensive nature'' to Taiwan, there is no way it can avoid a collision with Peking, which has recently said: ''Sales of weapons to Taiwan, whatever type they might be, constitute violation of China's sovereignty and an intervention in China's internal affairs.'' (New China News Agency commentary Nov. 24)
Behind the scenes, there is said to be hope that patient, quiet discussions will open the way to a continuation of limited American arms sales to Taiwan without provoking a crisis in Sino-American relations.
But the suspicion in Peking that President Reagan really wants to keep Taiwan forever in the American orbit remains strong. The corollary suspicion in Washington, equally strong, is that Peking really intends to take over Taiwan by force.
On both sides, emotions have reached such a point that the danger of a misstep through miscalculation cannot be ruled out. That is why former Vice-President Walter F. Mondale warned during his visit to Peking last month that Washington and Peking faced ''a delicate moment'' in their relations.
Diplomatic observers from countries with a stake in continued good relations between China and the United States have been distressed by the increasing stridency of polemics between the American and Chinese media.
Officially, neither side has made any irretrievable statements. But Washington naturally suspects that such publications as the New China News Agency and the People's Daily reflect Chinese government views. Peking meanwhile assumes that such journals as the New York Times and the Wall Street Journal express at least to some extent the opinions of influential congressmen and officials.
A New York Times editorial of Nov. 20 touched a particularly raw nerve here when it asked, ''Why should its (Peking's) Communist regime define American ties with an anti-Communist ally?''
The purpose of the editorial was to seek a way out of the impasse by suggesting that Washington sell a fighter plane less sophisticated than the F-16 or the F-5G to Taiwan.
But the implication that Taiwan was an ''anti-Communist ally'' reawakened suspicions that have never been totally laid to rest here: Namely, that in their heart of hearts, Americans still believe the old cold war ideology that all communists are enemies and all anticommunists are therefore allies.
There is also suspicion that despite recognition of Taiwan as part of China, Washington would prefer a Taiwan that remains permanently separate from China.
On the American side, the corresponding suspicion is that some day Peking intends to complete its 1949 victory over the Kuomintang (the Chinese Nationalists) by using force to take over Taiwan.
Washington does not oppose reunification of Taiwan with the mainland. It does oppose reunification by force. This attitude has been consistent throughout successive administrations, Republican and Democrat.
There is, therefore, a fundamental contradiction between the American and Chinese positions, which was recognized by both sides when President Carter normalized diplomatic relations with Peking in December 1978.
In Deng Xiaoping's words to American Ambassador Leonard Woodcock on Dec. 15 of that year, ''We will never agree to your selling arms to Taiwan, but we will set that aside in order to achieve normalization.''
Ultimately, the contradiction between the Chinese and American positions can be dissolved only if China and Taiwan themselves come to terms and agree to unification either in name or in fact.
In this sense Marshal Ye Jianying's nine-point proposal of Sept. 30 this year went a considerable distance toward meeting Taiwan's fears that Peking aimed simply to gobble it up.
Marshal Ye not only promised Taiwan ''a high degree of autonomy'' but said ''it can retain its armed forces.'' Asked why Peking should make such a pledge, a high Chinese military official said, ''So their fear of us may be lessened.''
If Taiwan is in fact allowed to keep its armed forces, it must obviously be free to equip and arm these forces from some source other than the mainland it fears. Otherwise the pledge would be meaningless. In its present mood, however, Taiwan is not about to seek clarifications from Peking, and Peking itself so far has refused to give these clarifications to any other party, including the US.
In contrast to its polemical mood towards the United States, Peking has been all sweetness and light toward Taiwan. In a recent interview in the monthly Liao Wang, one of China's top officials concerned with Taiwan policy, Liao Chengzhi, said that Marshal Ye's proposals ''were not put forward as an expedient, or from strategic considerations, or as a propaganda offensive.''
The proposals, Mr. Liao continued, represented ''national policy at the highest level, a long-term strategic target which will remain unchanged.''
Although the Taiwan authorities ''were acting like fretful children,'' their present responses ''should not be taken too seriously'' and Peking was quite willing to be patient.
Some analysts conclude that somewhere in this tangled three-cornered relationship between Peking, Washington, and Taipei, the effort to find a solution at least tolerable to all sides must be sought.