His analysis, posted online at the Nautilus Institute, a Berkeley, Calif., geopolitical think tank ( www.nautilus.org ), asserts that North Korea would enhance its own national security, gain critical economic assistance and avoid American-initiated “regime change” by exploding one of the handful of A-bombs in its arsenal. He says Pyongyang has good reason to bet that none of the region’s big powers—the United States, China, Russia and Japan—will do more than voice strenuous objections and impose symbolic punishments. “If the DPRK [North Korea] successfully carries out a nuclear test, it will be accepted as a de facto nuclear country after a period of international sanctions, as India and Pakistan were reaccepted by the United States and by other mainstream countries … several years after they conducted nuclear tests in 1998,” he writes.

A nuclear North Korea would also be useful to China in its Taiwan policy. To be sure, a nuclear test would cause Beijing, as broker of recent multiparty negotiations to end the nuclear standoff, to lose considerable diplomatic face. But North Korea also serves to neutralize the presence of American troops in South Korea, and a nuclear North Korea would accomplish this even better. “The main task now is ‘opposing Taiwan independence’,” he writes. “In this respect, the DPRK at least puts in check the tens of thousands of US troops in South Korea and … helps China divide the military threat of the US military forces in the Asia-Pacific region.”

That viewpoint echoes a historical perspective widely held by Chinese intellectuals—that the 1950-52 Korean War, which brought China and the United States into bloody combat, scuttled Chairman Mao’s impending invasion of Taiwan. Preventing unity on the Korean Peninsula underscores China’s persistent efforts to prop up North Korea economically, a practice Shen doesn’t expect will cease even after a nuclear test north of the 38th parallel. “Our country only needs to symbolically take part in the sanctions that the international community will surely impose on the DPRK,” he says.

Still, Beijing’s influence over the ally it rescued from certain defeat 55 years ago remains limited, says Shen. “It is impossible for China to apply excessive pressure on [North Korea] … while not harming our country’s fundamental interests,” he writes, calling China’s 12-year diplomatic effort to halt North Korea’s nuclear program “a failure.”

Washington has the most to lose if Pyongyang pulls the trigger, says Shen. America “has its hands tied in the global arena” and can’t easily divert military resources away from Iraq or Afghanistan, he says. The United States also fears North Korea’s conventional and nuclear deterrents and would face stiff opposition from every government in the region should it apply President George W. Bush’s doctrine of pre-emptive war. Even moderation is risky; by not thwarting Pyongyang’s nuclear ambitions, he says, Washington might unwittingly compel allies Japan and South Korea to develop atomic arsenals of their own.

Shen is not alone in his prediction that Pyongyang will test a bomb very soon. “I think you have an even chance of a nuclear device detonation by the end of the year,” warned former U.S. deputy secretary of state Richard Armitage during a conference in Seoul late last month. “It’s the next rational escalation point.” Whatever the fallout.