A CIA report that North Korea may have a long-range rocket that can strike the US West Coast provides yet another reason for China to rein in its troublesome ally.
Chinese leaders have openly rebuffed President Bush's request that they exercise their clout over economically ailing North Korea, which receives nearly half of its foreign aid from its giant (and fellow communist) neighbor.
Russia, which has residual post-Soviet ties with Pyongyang, appears willing to help the US in dealing with the wily Kim Jong Il. Why not China?
Perhaps Chinese leaders know Mr. Kim won't take his threats against the US too far. Any serious provocation by North Korea against Americans would likely lead to quick annihilation of Kim's regime.
Kim has trapped himself by creating new weapons for diplomatic clout, only to face a Bush policy of preempting such threats. Kim's survival tactics now threaten his own survival.
China probably also prefers the status quo of a divided Korean peninsula, which may come to an end if Chinese pressure, such as withholding food or oil aid, simply forces a collapse of Kim's regime. A reunited Korea might then allow US forces, now stationed in South Korea, to move right up to China's border. For a country that already fears American "encirclement," that's to be avoided.
(South Korea, too, prefers to avoid reunification anytime soon because of the huge expense that would come with absorbing its poor cousins. And unlike the US, the South isn't the target of these latest threats from North Korea.)
Despite these disincentives for Chinese involvement, the North Korean crisis should serve as a test for China's growing diplomatic role in Asia.
For the sake of stability and economic growth, Beijing has dropped its belligerent tone toward Taiwan for now, and has been slowly competing with Japan for regional influence. Last year, it agreed to set up an economic zone with 10 Southeast Asian nations and signed a declaration that may ease tensions over claims to South China Sea islands.
China may see North Korea as a containable nuisance, as France and Germany see Iraq.
But Beijing should beware of losing its cordial ties with the United States if Washington's frustrations build over Beijing's lack of cooperation on North Korea. That frustration is already evident in Washington's reported development of a sanctions plan against North Korea.