For 13 years, much of the formidable energies of the Soviet Union and China has been absorbed by their mutual armed confrontation, greatly to the benefit of Eurasian stability and American interests. Since such ''good'' things usually do not last forever, and since the two adversaries were once allied with each other , third parties tend to watch for signs that they might be coming together again.
The Soviets have naturally tried to exploit the current winter of discontent in Sino-American relations, which has grown mainly from Peking's reluctance to tolerate indefinitely what it was warned at the time of normalization to expect, the continued sale of ''selected defensive'' American arms to Taiwan. A prominent Soviet Asian specialist, S.L. Tikhvinsky, spent the second half of January in Peking, although there is no evidence that he made substantive progress during his discussions.
In an interview published on Feb. 14, the anniversary of the signing of the Sino-Soviet treaty of alliance in 1950, Soviet Premier Nikolai A. Tikhonov advocated unspecified steps to improve relations between Moscow and Peking. For its part, Peking has privately proposed an increase in its trade and cultural relations with Moscow, perhaps as a means of pressuring the United States. On the other hand, it did not send a message of condolence on the death of the senior Soviet ideologue, Mikhail Suslov, which occurred during the Tikhvinsky visit.
Occasional olive branches such as these appear to reflect little more than an understanding that the Sino-Soviet confrontation benefits others including the US and a special unwillingness on the part of China, even though it is by far the weaker party to the confrontation, to let itself be taken for granted by its new American friends on the theory that it has no Soviet card to play.
None of this affects the deep hatred and distrust that Moscow and Peking feel toward one another for a combination of ethnic, historical, ideological, and political reasons. It does not evaporate their boundary dispute or the presence near the Sino-Soviet border of roughly one-quarter of Moscow's military power.
The Chinese are too profoundly angered by the bullying that they have undergone at Soviet hands since 1969 to be actively interested in an accommodation, and they are too strong to be coerced or Finlandized by anything less than a major Soviet attack. They know that Moscow will not accept their demand for an unconditional ceasefire along the common border, the removal of most Soviet troops from the border region, and a Soviet military withdrawal from Mongolia, Vietnam, and Afghanistan. They appear to believe, and correctly, that the real Soviet terms for a political accommodation would be unacceptably high: Soviet ''advisers'' in key posts within the Chinese system, the ''coordination'' of the two military establishments under Soviet control, a similar coordination of policies toward third countries, especially the US, etc.
This of course is much more than the US has ever demanded of China, and yet we were unable to achieve anything better than an adversary relationship with China while we were perceived in Peking as a bully and a threat, as we were until the late 1960s and Moscow is now.
Nothing can be taken for granted in international politics, but it does appear that the Sino-Soviet confrontation is here to stay for at least a while longer. An accommodation is conceivable and would be a serious problem for the rest of the world, but if one were actually in the making the signs would almost certainly be louder and clearer than anything to that effect heard in recent years. At the other extreme, a major Sino-Soviet war is also conceivable and would have a seriously destabilizing effect on the Far East and the world, but fortunately the disincentives are very powerful for both parties.
The new relationship between the US and China also cannot be taken for granted, but it too is apparently here to stay for the ''foreseeable'' future. Both parties need it as an aid in coping with the Soviet Union, whose power and assertiveness have been growing at a rate alarming to both. The Chinese need the relationship more than we do, but they should not be underestimated for that reason. They are already making an important contribution by tying down powerful Soviet forces that otherwise could be redeployed against NATO, and the contribution will probably grow as their economy gradually develops.
Both parties need to behave in a more mature way toward each other, the Chinese by not pressing so hard on Taiwan, the Americans by not getting nervous whenever Peking scowls in their direction or turns a smiling face toward Moscow.