Soviet Union plays its China card against the United States

The Soviet Union, while decrying what it sees as a hostile alliance between the United States and China, has moved to scale down its own longtime quarrel with the Chinese.

In offering to resume border talks with China, the Soviets are seen as hopeful of introducing a further complicating factor into the US-Chinese relationship. The Soviet proposal was disclosed Oct. 20 by Peking, which says it is studying the offer.

Perhaps significantly the Soviet offer came on the eve of Cancun summit where President Reagan and Chinese Prime Minister Zhao Siyang are widely expected to meet. Such a meeting could help determine whether Chinese-American relations progress further -or cool because of disagreement over Washington's insistence on arming Taiwan.

Chinese officials in Peking say the Soviet proposal deals only with the two countries' disputed border. But according to informed sources in Mosow cited by the Yugoslav news agency Tanjug, the purpose is to help start a general improvement in relations between the Soviet Union and China.

Some diplomats here speculate that Moscow also may be trying to counter what it portrays as a US-Chinese-Pakistani alliance against its client regime in Afghanistan. In addition, the Soviets may hope to lessen the regional isolation of the pro-Moscow regime in Vietnam.

Most diplomats here see the last two goals as all but impossible, at least for the time being, even should Peking agree to resume border talks. Nor are the Soviets given much hope of imperiling the US-Chinese relationship for the foreseeable future.

But renewed SovietChinese talks could conceivably serve to complicate Washington's ties with Peking, some diplomats say. Already faced with resolving the status of Taiwan in that relationship, the argument goes, the Chinese might choose to reopen talks with the Soviets as a signal to the Reagan administration that Peking need not put all its superpower eggs in one, US, basket.

"If the Chinese refuse talks," one Moscow diplomat said, "Moscow can simply accuse Peking of intransigence and move full speed ahead with its propaganda war with the Chinese." That verbal battle, by the way, has not noticeably quietened even with the Soviet negotiating offer.

"If the Chinese accept talks -even if they produce no real progress -the Soviets are still better off talking to Peking than not talking," the diplomat argued. "The Soviet-Chinese quarrel is not about to go away. But the less visibly fierce it is, the more complicated US-Chinese relations become."

This would seem particularly true on the eve of resumed arms talks between the Soviet Union and the United States. China has always feared it could become the loser in a workable system of detente between Moscow and Washington.

The Chinese still mistrust Moscow a lot more than they do Washington, and think Washington can help them a lot more economically and military than can the Soviets.

Peking still fiercely opposes the Soviet military presence in Afghanistan, and remains at bitter odds with Vietnam.