China's rapid modernization and the Soviet Union's ailing economy appear to be driving the two communist giants to expand their economic and technological ties. The success of their efforts, after more than 25 years of chilly diplomatic relations, say Western analysts here, will largely depend on whether economic realities can help them minimize their ideological differences.
``At least both sides recognize that it is no longer a `we win [or] they win situation,' '' says one Western diplomat.
Dividing the two nations is a decades-old struggle over ideological purity, with Moscow claiming that Peking has ``deviated'' from communist orthodoxy. For that reason, among others, Nikita Khrushchev cancelled Soviet aid to China in 1960 and withdrew all of the more than 10,000 Soviet advisers and technicians who were stationed in the People's Republic.
More recently, China has identified three obstacles to harmonious Sino-Soviet ties: the Soviet occupation of Afghanistan, Soviet support for the Vietnamese-backed Heng Samrin regime in Cambodia, and the massing of some 50 Soviet divisions along the Sino-Soviet border.
But now, China's enormous demand for raw materials and technical assistance and the Soviets' recognition that they need to reform their dilapidated planned economy appear to be steering the two countries toward some sort of reconciliation, at least on the economic front.
Last week, Chinese Vice-Premier Li Peng and visiting Soviet Deputy Prime Minister Ivan Arkhipov signed a protocol of economic and technological cooperation.
This latest Sino-Soviet meeting resulted from Mr. Arkhipov's December 1984 visit to Peking. At that time, Arkhipov was the highest-ranking Soviet official to visit China in 15 years. Both sides signed an accord calling for regularly scheduled economic meetings.
Since 1982, trade agreements between the border provinces of China and the Soviet Union have increased in both number and significance. Their value has soared from $400 million in 1982 to almost $2 billion last year. Both countries would like to boost that figure to $6 billion by 1990.
The Chinese export mineral products, meat, soybeans, textiles, tea, and light industrial products to the Soviets and import Soviet iron, timber, cement, soda ash, fertilizer, glass, trucks, and automobiles.
This May, river transport between the two countries will resume after a 20-year suspension, according to officials in Peking's Ministry of Communications. China says it will open the Tongjiang port at the confluence of the Songhua and Heilongjiang rivers. The Soviet Union is expected to reopen the Leninskoye port, upstream from Tongjiang. Cargo handled by both ports in the form of corn, soybeans, and timber is expected to rise from 100,000 tons this year to 800,000 tons by 1990.
Sino-Soviet technological exchanges are keeping pace with the burgeoning trade. The Soviets recently invited a Chinese delegation to tour nuclear-power facilities in the Soviet Union. And 15 Soviet technicians returned to China this year to begin refurbishing 24 of the 130 Soviet-built factories that were abandoned after the Sino-Soviet break of 1960. Another 50 Soviet technicians are expected to settle in northern China next year.
Beyond the economic benefits to be gained by China and the Soviet Union, Western observers in Peking see a Sino-Soviet rapprochement as a healthy, even desirable political trend. They say that a thaw might pressure the Soviets to force the Vietnamese out of Cambodia and make an isolated North Korea draw closer to South Korea.
Indeed, during the week-long meetings between Li and Arkhipov, Prince Norodom Sihanouk, a leader of the Cambodian resistance and president of the Coalition Government of Democratic Kampuchea, issued an eight-point peace plan from his Peking residence that called for negotiations with the Vietnamese-backed regime in Phnom Penh and its inclusion in a new coalition government.
While such members of the Association of Southeast Asian Nations as Thailand and Indonesia applauded the proposal and the Chinese called it ```magnanimous and flexible,'' the Vietnamese quickly rejected it. Peking promptly branded the Vietnamese response ``hypocritical.''
Even if relations between the two countries improved dramatically, ``China would probably continue to turn to the West for high technology,'' says one Western diplomat.
Moreover, some liberal Soviet economists have begun to wonder, in several magazine articles, if China might achieve economic success before the Soviet Union does. ``The big Soviet concern is for its external position,'' says a Western resident of Peking who has lived in Moscow. ``A successful, alternative communist model, particularly a big continental economy like China's, could put enormous pressure on the Soviets.''
Some suspicion would probably remain even in an improved Sino-Soviet relationship. The Soviet Embassy in Peking, for example, would like to build an 18-story annex on the grounds of its compound. But a Chinese housing official insists that zoning laws will prevent the structure from rising more than six storys. ``After all,'' says this Chinese, ```we can't have them spying on the entire city.''