CLEVER, THOSE Chinese. They have now split the old "China lobby," more recently known as the Taiwan loby, meaning those Americans who favor a special relationship with Taipei over one with Peking. The Ray Cline branch -- he is the Reagan-connected Taiwan hand who was savaged again by Peking only yesterday -- remains unreconstructed. The Anna Chenault branch, however, is in camp. The Chinese-born Washingtonian spoke out sharply against the American normalization of relations with the People's Republic in 1978, but last weekend she was in Peking gently lauding the virtues of the "open mind." Given her political history and her high standing in both Nationalist Nationalist circles in Taiwan and Republican circles in Washington, here visit produced as interesting a flurry of speculation as the transition has so far seen.

But she was not the only special visitor to Peking. Sen. Ted Stevens (R-Alaska), who flew with Mrs. Chennault's late husband in World War II, also was there. at a press conference, he invited the Kremlin to understand that his visit was "not accidental . . . . I think we are seeing a new attitude of the Soviet leaders [in Poland, Vietnam and Afghanistan], and they have to understand there is a new generation in our country dealing with problems related to them." He could not rule out sales of lethal military equipment to China, he said. The Chinese have spent the last four years importuning the Carter administration to stand up more resolutely to the Kremlin. Presumably they would be as pleased to buy those arms as the Soviets would be angry and alarmed.

The real Peking enigma, however, remains Ronald Reagan, a supporter of the China/Taiwan lobby for decades. In August he eased off his threat to restore "official" relations with Taiwan; that would refreeze relations with Peking instantly. But he has cooly refrained from reaffirming the Nixon-Chou Shanghai communique, the basic text of U.S.-Sino reconciliation. Just how the president-elect will interpret the command of the Taiwan Relations Act -- it's tricky to have a law laying down American policy -- to arm and otherwise protect Taiwan is unclear. Nor is it certain how he will fit China into his basic policy of containing Soviet power. Arms sold to Peking for that purpose could, theoretically, embolden Peking to threaten Taiwan. Not selling arms could have its own fallout. Until now Mr. Reagan has merely spoken words about China, and yesterday Secretary of State-designate Alexander Haig added his own. The general showed a sure grasp of the possibilities and the pitfalls, while making it clear that he has yet to go deeply into the subject with the president-elect. All the hard policy choices lie ahead.