Peking — The first substantive step in improving Sino-Soviet relations is up to Moscow , Chinese sources say.
These sources have repeatedly told both foreign visitors and resident journalists that while China wants peaceful relations with the Soviet Union, Moscow must show by deeds rather than words that it wants the same.
Nevertheless, as the two former allies prepare to resume border talks at the vice-ministerial level in Peking after a three-year hiatus, there is lively interest in Washington, Tokyo, and West European capitals over the extent to which Sino-Soviet relations can in fact be improved.
Deng Xiaoping, China's de facto leader, has given up many party and government positions, but retains the chairmanship of the party's Military Commission, which controls the armed forces. Mr. Deng has told recent visitors that China is looking at least to have the Soviet Union thin out its 40-odd divisions along the 4,000-mile Sino-Soviet border and in Mongolia.
Moscow is clearly interested in upgrading the public image of Sino-Soviet relations and, to a degree, Peking is willing to do the same. Cooler Sino-American relations caused by the Taiwan dispute may have something to do with this. But basically Mr. Deng and his associates have been moving in this direction ever since they came to power.
Exchanges of scholars and athletes between China and the USSR have resumed to a limited degree. The Chinese are also interested in how the Soviets manage their vast, centralized, bureaucratic, socialist economy. China has studied East European experiences, but only the Soviet Union's size and scale compare with that of China.
With no sharp ideological disputes of the kind that characterized the days of Mao Tse-tung and Nikita Khrushchev, the Chinese are ready to see how the Soviet economy has fared in the 20 years since the Sino-Soviet split.
But more basic than these interests is the fact that Mr. Deng and his associates, by committing themselves to a 20-year program of raising China's standard of living and of modernizing the Chinese economy, require a long period of peace both at home and on their borders.
They have not entirely abandoned Mao's thesis of the inevitability of a third world war. But they have emphasized the possibility of delaying this dreaded scenario.
Their actions toward the Soviet Union have been circumspect despite their anger over the Soviet invasion of Afghanistan and Soviet support for Vietnam's occupation of Kampuchea.
China's strategy against the possibility of a Soviet attack is essentially one of defense in depth. China is prepared to yield up territory in the initial stages of an attack and is confident of its subsequent ability to bog down Soviet troops in an interminable peoples' war, far more ferocious than anything the Soviets have experienced in Afghanistan.
That, and their modest strategic nuclear strike capability, is what gives credibility to their defense posture. They say they have no armies on the border poised to strike deep into Soviet territory. Unless the Soviets have aggressive designs of their own there is no justification for the steady build-up of Soviet forces on the border and in Mongolia, Peking says.
China does have a program to modernize its armed forces, but this is a long-range plan. Chinese shopping expeditions to Europe and the US have shown no great sense of urgency about buying antitank weapons systems or fighter aircraft capable of standing up to MIG-23s and MIG-25s.
The armed forces have accepted Deng's logic that until the total economic pie grows larger, they cannot expect substantial increases in their own budget.
If Moscow accepts China's assertions, it should be willing to reverse its steady build-up of forces, including the SS-20 mobile nuclear missile that has so alarmed the West Europeans. At least that is how Peking reasons.
If Moscow does make a decision in this direction, then Sino-Soviet relations could move beyond images and atmospherics into substantive issues. Deng and company are waiting to see what the response from the Kremlin will be.