Early in my stay in Peking, I met a friendly Soviet diplomat who had been in China in the heyday of Sino-Soviet friendship during the early 1950s. This diplomat was convinced that someday Peking would again turn to the Soviet model it has progressively discarded since it broke with Moscow at the end of the 1950s.
''After all,'' he said, ''China is a large socialist country, and so is the Soviet Union. ''China is looking for models now to Yugoslavia, to Hungary, to some of the Western countries.
''But the Chinese leaders will soon find out that they can only go so far with their 'open-door' policy toward the West because, after all, these are bourgeois democracies while China is a socialist (i.e., communist) country.
''Hungary and Yugoslavia are socialist. But their examples can be relevant only in part for a country as enormous and as diverse as China is. I am convinced that some day, after they have finished experimenting with the Yugoslav model, or the Hungarian, or even the Japanese, they will come around to seeing that the country in the world most like themselves is the Soviet Union.
''They will see that in the 20 years and more since relations soured between us, we have made considerable economic progress, entirely within the context of socialism, under strong centralized planning and leadership,'' he said.
Last year, when I visited Moscow, a couple of Soviet scholars put forward much the same sort of argument. Soviet interest in improving relations with Peking was long term, not short term, they said. Moscow was prepared for a slow, gradual improvement in Sino-Soviet relations as Peking became more and more disillusioned over the limits of economic cooperation with the West.
I put this thesis to a well-informed Chinese friend soon after the death of Soviet leader Yuri Andropov in February, but before the abrupt Soviet announcement that First Deputy Premier Ivan Arkhipov's visit to China in mid-May had been postponed.
My friend smiled. ''What you have just outlined is what Moscow hopes will happen. I don't think it's a very likely scenario.
''First of all, early in the 1950s we did wholeheartedly follow the Soviet economic and political model. Our economy was tightly controlled by the central authorities. We gave top priority to heavy industry, to accumulation rather than consumption. Even after the political break with Moscow, we retained the Stalinist economic model. The results, as you can see, have been pretty disastrous. We have fallen far behind countries like Japan, whose economy was in ruins after the war.
''We sent thousands of students to the Soviet Union to study engineering, science, technology. But these students did not necessarily become pro-Soviet after they returned to China.''
Another friend, himself an engineer, is more explicit on this point. ''The greatest contrast I find between the students that went to the Soviet Union in the '50s and the students who are going to the US now,'' he said, ''is that very few of the Soviet returnees became pro-Soviet, while almost all the American returnees are enthusiastic both about the treatment they received and the studies they pursued.
''President Reagan was quite right when he said he wished there were 100,000 Chinese students in the US instead of 10,000. The greatest investment America could make in China today is not in dollars and cents but in welcoming tens of thousands of our students into their country.''
This friend teaches at a technical institute and said he was embarrassed when fledgling engineers asked him, ''Why do you think China is so backward today, while Japan is so prosperous? Don't you think it's because China is socialist while Japan followed the Western model?''
All he could say in response, he told me, was: ''Socialism is a superior system. But in the 1950s we followed the Soviet model, and that is why we made so many mistakes.''
A student raised his hand. ''Teacher,'' he said, ''I think socialism is good at one thing -- it is good at making mistakes.''
On May 9 this year, Moscow suddenly informed Peking that it was postponing Mr. Arkhipov's visit to China, which had been scheduled to start the following day. Mr. Arkhipov, who was chief Soviet aid adviser in China during the early 1950s, would have been the highest Soviet official to visit China since Premier Alexei Kosygin's Peking airport meeting with Chou En-lai in September 1969.
The abruptness of the announcement naturally roused all manner of speculation both in Peking and in other capitals. The suggestion I found the most intriguing came from a senior Chinese journalist who said that Moscow may be concerned over the success of the economic reforms being adopted by the Chinese party and government under the guidance of Deng Xiaoping and his associates.
Chinese agriculture is in fine shape, with three successive record harvests. Peasants are rich and getting richer. The open-door policy toward foreign investment is being vigorously pursued. Special economic zones have been set up where foreign investors enjoy tax holidays and other privileges. Fourteen coastal cities have been given wide new powers to attract foreign partners. Consumer goods production is being given priority over heavy industry. And so on and so forth.
The journalist cited a recent article by a Soviet theorist warning that the Chinese way was not truly Marxist-Leninist and was therefore not a model to be followed. Moscow seems to fear, the journalist said, that the Arkhipov visit, if allowed to take place, would be interpreted as an endorsement of the ''Chinese way to socialism,'' when from Moscow's viewpoint there was only one proper way -- its own.
Said another Chinese journalist, ''Even if Moscow removes the three obstacles and thus makes it possible for Sino-Soviet relations to be normalized completely , things will not be as they were in the 1950s.'' The three obstacles which Peking wants Moscow to remove are, first, to withdraw its troops from Afghanistan, second, to stop supporting Vietnam's occupation of Kampuchea (Cambodia), and third, to reduce its own military strength along the Sino-Soviet border.
''In those days, the Soviet Union was the center of world communism and thought it had the right to command China,'' the journalist said. ''Today we will no longer accept such a relationship -- we didn't do it even in the 1950s.
''True, we are both socialist countries. We both believe in Marxism-Leninism and our parties are organized in the same way. But how we understand Marxism-Leninism and what we do with our respective organizations is quite different.
''Their understanding of Marxism-Leninism allows them to invade Afghanistan and help the Vietnamese occupy Kampuchea. Their understanding of Marxism-Leninism allows them to fish in troubled waters in Africa and to try to impose their ideology on others.
''This is not our understanding of Marxism-Leninism.
''As for organization, since the third plenum (December 1978, when Deng Xiaoping's reformist line was adopted), we have taken new measures to strengthen and increase democracy both within and without the party. In local elections, we put up more candidates than there are seats, so voters have a choice. It is true that once the party line is established on a particular policy, everyone must support it. But in the period leading up to the adoption of that line or policy, there is a great deal of discussion and debate and many different opinions are voiced, sometimes quite vehemently. In short, we are proceeding in a direction which the Soviet Union does not understand and cannot tolerate.''
Some Western observers in Peking would not agree entirely with this analysis. They note that it is too soon to say whether Deng Xiaoping's reform policies will prove successful in the long run. A string of poor harvests, another downturn in the world economy, or China's failure to find offshore oil in the quantities it is hoping for -- there are many factors that could upset the leadership's calculations and force a retreat from liberalizing reforms at home and an open door abroad.
Some diplomats believe there is restiveness within the armed forces and a desire even among younger officers for military cooperation with Moscow. If Deng were to die or to be incapacitated suddenly, his proteges -- Premier Zhao Ziyang and General Secretary Hu Yaobang -- may lack the prestige to keep all potential troublemakers under control.
But few dispute that the era of monolithic communism has passed into history and that the Chinese way to socialism has already diverged significantly from that of Moscow. There is strong evidence, both in the countryside where four-fifths of all Chinese live, and in urban areas, that Dengist reforms enjoy widespread popular support.
For the reforms to succeed over a long period of time, China needs a peaceful environment around its borders. The attempt to improve relations with the Soviet Union should be seen in this context, Western observers here believe, rather than in the context of a possible revival of the Sino-Soviet alliance.
Ultimately, China is so huge, its problems so unique, that neither Moscow nor Belgrade, Washington nor Tokyo, can serve as an adequate model. China is sui generis. Step by painful step, its leaders and its people will have to tread their own path to modernization and development.
Next: Why an obscure English novel, ''The Gadfly,'' is popular in China.