LEONID BREZHNEV, growling, tells the United States not to "play the Chinese card," a policy he describes as short-sighted, dangerous and cynical. Thus he advertises the Kremlin's paranoic fear that the United States will make open anti-Soviet cause with the People's Republic of China. But he should relax. Barring grievous Kremlin Provocation, the administration is not about to unbalance its Soviet policy and hook up with Peking to resume fullscale cold war. That would be a dangerous policy. President Carter said as much the other day.

Mr. Carter did not, however, say all that he might have said. He did not say, to Mr. Brezhnev, that the administration does not require Soviet consent to improve ties with a country with which the United States shares many interests. He did not say, to Americans, that good relations with Peking not only have their own value but add to the United States' ability to "contain" the Kremlin. Everyone knows this, Mr. Brezhnev included. It was the basis of Richard Nixon's outreach to Peking in 1972. Mr. Carter did not have to avow what is plainly not the case - that the United States will not "ever" play the Chinese against the Soviets. Washington has made that routine in its diplomacy for six years, and the end, one trusts, is not in sight.

One thing you must give Mr. Brezhnev: He has correctly detected a pickup in the tempo of the long, slow American effort to normalize relations with the People's Republic. Full "normalization" means eventually the transfer of full diplomatic recognition from Taipei to Peking and the breaking of formal military ties to Taiwan. Whether Mr. Carter thinks the advantage in pleasing a new friend outweights the signal of letting down an old one, and whether he is ready to pay the political price, seems to us uncertain now. In any event, the administration has found that, short of normalization, there is useful slack to be taken up with Peking. Zbigniew Brzezinski's recent trip was one part of it, the dispatch of a high-powered scientific mission is a second, further cooperation in China's economic development a third, a readiness to see Europe sell Peking military equipment a fourth, and a new tendency to celebrate Sino-American ties in public a fifth. The Chinese no doubt wonder whether these steps are a prelude to, or a substitute for, full normalization. The question is not open to answering now.

The United States wants a "strong and secure" China, Mr. Brezezinski said in Peking. The State Department has since publicly underlined that position. It makes sense as long as Washington's and Peking's common interest in a stable Asia and a contained Soviet Union remain firm. That is not "playing the Chinese card" - a phrase that should be reserved for the virtual abandonment of hopes for improved ties with Moscow. It is simply prudent diplomacy.