There is a perceptible quickening of the tempo in the triangular game being played between Russia, China and the United States. The visit to Peking by President Carter's national security adviser, Zbigniew Brzezinski, follows a tour of the Soviet Union's Chinese borderlands by Party Secretary Leonid Brezhnev. Moscow has sent its chief negotiator on Sino-Soviet matters, Leonid Ilyichev, back to Peking, despite China's recent rejection of yet another Soviet offer to work out a settlement between the two countries. And the Kremlin has made an unprecedented public apology to China for a border incident in which Soviet troops manhandled a number of Chinese civilians.

But all that provides only the external setting for Peking's own debate on how to handle China's relationship with the two superpowers. The major issue in the debate is whether China should reestablish a friendly relationship with the Soviet Union. That is linked directly with the struggle over domestic policy now in progress in Peking. The policy debate, as traced in these columns recently, suggests that the struggle is between those who want to proceed with de-Maoization, as represented by Vice Premier Teng Hsiao-ping, and those who are less eager to take that course, as represented by Party Chairman Hua Kuo-feng.

The right-wing policy of modernization is urged by Teng. The left-wing policy of sticking to socialist principles is favored by Hua. the extreme-left policy of reviving Mao's radical program is advocated by the many followers of the e "Gange of Four" who are being constantly denounced by the Chinese press. Even though the Gang, led by Mao's wife, was overthrown after his death, a strong Maoist faction in the army is making it difficult for Peking to disregard the views of the extreme left.

The modernization urged by Teng requires mobilization of the country's resources for the development of industry and agriculture, and this means that less would be available for the army. That is one reason why, apart from any ideological considerations, there is also strong army opposition to Teng. He has promised that the modernization of the economy would also lead to the modernization of the armed forces, but the economy must come first. Some members of the military opposition contend that the modernization of the army entails the abandonment of the Maoist guerrilla strategy of "people's war," and that that would lead to defeat if war broke out with Russia.

A recent article in the party journal Red Flag disputed their "slanderous" view that to speed up the modernization of the army was to "negate" the concept of people's war. The opposition maintains that an army that is trained and deployed to fight a people's war cannot at the same time be equipped and structured to fight successfully a modern war. The opposition's argument makes good military sense.

Teng seeks to blur the distinction by urging the army to prepare to fight a people's war "under contemporary conditions." But that means that he wants to retain the name "people's war" while infusing it with a modern content. The modern and costly arms that would make that possible are obtainable only buy purchase from abroad in the short term, and by the modernization of the economy in the long term.

But it is inconceivable that foreign-arms purchases could turn China's huge army in a short space of time into a modern force able to stand up to Soviet military might in a war fought with modern weapons and tactics. Teng's modernization program - whether for the economy or the army - needs a lot of time. It needs an ensured peace with Russia, stability on the border and a political atmosphere in which China could afford to concentrate on economic reconstruction without being repeatedly reminded by its military that war is just around the corner.

What it needs, in short, is a srttlement with Russia. That is the real foreign-policy issue in the debate about modernization, which is seemingly concerned with internal matters. But if Teng wants a settlemant with Russia, he must obtain form the Kremlin the concessions that would make it possible to persuade the other Chinese leaders that the deal is worth having. Brezhnev, too, wants a settlement, but he is not at present able to make the far-reaching concessions Teng needs, Brezhnev's recent tour of the borderlands was designed in part to assure the party and military leaders of those areas - who form the core of the Soviet anti-China lobby - that their concerns would not be over-looked. The speeches they addressed to Brezhnev during his tour made it clear that they were more concerned about the danger from China than some of the leaders in far-away Moscow seemed to be.

By inviting Brzezinski to Peking at this time, Teng was telling the Kremlin that if it fails to make a better offer China could develop a closer relationship with the United States, both political and military, Moscow can either help Teng obtain the peace and stability he wants for China, or it can damage the Soviet Union's own security by a policy that results in stronger, more effective, U.S.-China ties.

Washington has, of course, its own reasons for sending the Brzenzinski mission to Peking, and one of these is that it wants to keep Russia and China as far apart as possible. But Peking is using the Brzezinski visit to make the Kremlin pay a higher price for a Sino-Soviet repprochement, and the signs are that it is succeeding. The prompt and unprecedented Soviet apology for the border incident may be taken as reflecting something of the mood of the Sino-Soviet negotiations now being conducted with such secrecy in Peking.