ALBANIA, WHOSE APPARENT craziness conceals great cunning (or is it the other way around?), broke 17 years of "unbreakable friendship" with China the other day, alleging ideological infidelity. Frankly, what the step says about Albania doesn't interest us very much. But since Albania is the closest thing going to a weathervane of Marxist purity, the step is an intriguing comment on China. Put next to the expulsion from the Communist Party of the radical Mrs. Mao and her "Gang of Four," and the rehabilitation of Teng Hsio-ping, it says that the post-Mao People's Republic is settling down in ways compatible with American interests.

Mr. Teng, 73, is one of the few poeple left at the pinnacle of Chinese politics who stands conspicuously for a particular set of policies. A protege of the late moderate Chou En-lai, he stands for economic growth or, more precisely, for not letting China's ravenous economic needs be unduly subordinated to other considerations. Thus, apparently, he would pay some people more if it helped raise production; buy foreign technology and even borrow foreign money as needed; reduce the disruptions of ideological campaigns like the "Cultural Revolution," and so forth. Moderate "capitalist road" policies like these, requiring good relations with the industrialized democracies, drive the Albanians up the wall. But Albania, with the lowest standard of living and one of the smallest populations in Europe, has requirements very different from China's. And so the old weathervane - as goes Albania, so goes China - no longer works. Mr. Teng and his colleagues evidently intend not to go Albania's way.

There is now an American consensus, shared even on the right by those with scant sympathy for Peking, that, whatever happened in the past, there is no longer any reason to consider China a menance to the United States. Aside from Taiwan, the two governments have little to disagree about. In the 1970s, China's fear of Russia, and the United States' perception that it could use Peking to keep pressure on Moscow and to enhance stability throughout Asia, produced an accomodation. The two agreed in effect to postpone the Taiwan question in order to enjoy benefits on other levels.

That is where Peking and Washington are now. Along with the existing strategic rationale for a close Chinese tie to Washington, Mr. Teng's rise confirms an economic and political interest, on China's part, as well. This is all the more welcome for coming at a time when the post-Mao turbulence in Peking had cast some doubt over whether it wished to continue the Nixon-Mao effort to improve Sino-American relations. Secretary of State Vance is about to visit Peking for what will be the first high-level contact between the two new "administrations." That Mr. Teng, who received President Ford, as well as Party Chairman Hua Kuo-feng, will be there to receive the Secretary would seem to bode well.