THE DIFFERENCES between the two great communist states in their attitudes toward foreigners is endlessly fascinating. The Russians invariably assume that the visitor is, if not actually a spy, at least a subversive influence from which the population must, as far as possible, be shielded. The striking thing about the Chinese, in contrast, is their cool self-confidence. A current example is the joint graduate center that Johns Hopkins University is establishing with Nanjing University.

Classes begin in September. The first year's 22 American and 43 Chinese students are to live and work together, each of the Americans with a Chinese roommate. Both universities are to contribute faculty, and the courses get into a number of sensitive subjects -- recent history, the structure of the two economies, Mao's thought (taught by a Chinese scholar in Chinese) for the Americans, American political institutions (taught by an American in English) for the Chinese. The library is to be half Chinese books, half American and European, on open shelves -- the very thought of which would threaten any right-thinking Soviet with cardiac arrest.

The Chinese are engaged in a sweeping reorganization of higher education in general, to produce more people with the abilities that a modern economy requires. The presidents and vice presidents of 11 Chinese universities have been at Johns Hopkins in Baltimore to meet some of their American counterparts. The Chinese are looking carefully at foreign models as they rebuild their own system, and the exchanges back and forth are widening. It's particularly remarkable when you consider that the country was almost totally closed to visitors for nearly a generation after the revolution.

Another indicator of the Chinese attitudes is the number of students they permit to study in this country, confident that most will return to China. There are currently more than 10,000 Chinese students at American colleges and universities, compared with hardly more than 200 Russians. The flow in the opposite direction, to China, is now limited more by lack of facilities than political constraints. John Hopkins' joint venture is an adventurous and promising attempt to widen those opportunities.