North Korea's curious brand of nuclear brinkmanship and blackmail will become a recurring nightmare for the United States and its allies in the region unless a longer-term policy of preemptive containment is implemented to prevent Pyongyang from obtaining the materials to develop nuclear weapons.

The current spate of diplomacy may be useful -- perhaps even successful -- in managing the short-term fallout from Kim Jong Il's decision to restart his nuclear reactors and pull out of the Nuclear Non-Proliferation Treaty. But such well-intentioned efforts can't quash the North Korean leader's long-term nuclear ambitions. They also put Washington in the awkward position of being compelled by its friends to engage with a regime whose repudiation of every international norm for state behavior offers no basis for engagement.

As the U.S. proceeds, it must avoid anything that appears like negotiating with a terrorist regime.

At the other end of the policy spectrum, preemptive military solutions like attacking North Korea's nuclear or missile installations could well cause Pyongyang to retaliate against Japan and South Korea with a blitzkrieg of troops and missiles. And threatening Kim's nonexistent economy with further sanctions is little more than bluster.

A new approach is needed to adequately address the North Korean threat. Japan, Australia and South Korea are currently engaged in diplomacy with Pyongyang. They should, in their talks, insist on the near-term removal of nuclear stockpiles as a prerequisite for food and fuel that would be provided for nonnuclear electricity production. Russian natural gas from deposits near the Korean peninsula could replace any need for nuclear power, while also giving Moscow an incentive to stand firm against North Korean nuclear actvities.

At the same time, a U.S.-led alliance needs to find ways of preventing materials necessary to weapons production from getting to North Korea. This would require firm commitments from China -- and, perhaps more important, Pakistan -- to stop providing Pyongyang with nuclear components, particularly the gas centrifuges that form the heart of uranium enrichment plants and the ring magnets that are vital to centrifuge function. Bomb designs, particularly the specialized bomb casings needed to house highly radioactive uranium cores and spherical implosion trigger devices needed for detonation, must also be stopped at the source.

Last month's sale by China of 20 tons of tributyl phosphate to North Korean agents, as reported in the press, demonstrates the magnitude of the problem. This is a key chemical needed to extract plutonium from depleted uranium fuel rods in a process known as "purex." The Chinese shipment was enough to extract plutonium for four to five bombs from the approximately 8,000 spent fuel rods North Korea has.

Efforts must be directed toward preventing any more of the chemicals needed to separate plutonium from depleted uranium fuel rods from reaching North Korean plants. Plutonium reprocessing would allow the North Koreans to miniaturize nuclear cores for missile warheads -- or worse, to shape them into small tactical weapons for sale to terrorists on the black market. If Beijing continues to enable Pyongyang's plutonium separation, it must also accept that such cooperation could spark a decision by Japan or South Korea to develop nuclear weapons.

More troubling still is the specter of Pakistani cooperation with North Korea. Islamabad vehemently denies having provided North Korea with any nuclear assistance in the past, but mounting intelligence data and forensic evidence suggest otherwise. The same South Korean intelligence report that exposed the existence of the uranium enrichment facility that sparked the U.S. confrontation with North Korea last fall also reportedly noted remarkable similarities between centrifuge components bought by North Korea for its plant and those known to be used by Pakistan at its enrichment facilities.

Press reports have repeatedly documented how a North Korean missile proliferation company, Changgwang Sinyong Corp. (CSC), provided missile parts to Pakistan for its Shaheen and Ghauri missiles, although the company has been sanctioned by the U.S. State Department only for its sale of missile components to Yemen and Iran.

CSC's chief procurement officer in Islamabad during the late 1990s, Kang Thae Yun, doubled as economic counselor at Pyongyang's Islamabad embassy. His wife, Kim Sa Nae, was mysteriously gunned down in Islamabad on June 7, 1998, a week after Pakistan successfully detonated five nuclear devices based largely on Chinese designs.

According to a senior Pakistani police source who filed the murder report (which was later leaked to Western journalists and published in November 1998), Kim was shot by North Korean agents working at Pakistan's top-secret nuclear facility, the A.Q. Khan Research Laboratories in Kahuta, who feared she was going to defect and provide Western intelligence agencies with hard evidence of Pakistan's assistance to North Korea in developing its fledgling nuclear program. Islamabad officially maintains that the murder stemmed from a kidnapping attempt gone awry.

But such nuclear shenanigans -- which admittedly happened under a different regime at a time when U.S.-Pakistan relations were severely strained -- must be curtailed. The Bush administration must hold its ally to answer, even if privately, about the exact extent and nature of assistance Islamabad provided Pyongyang in its uranium enrichment and bomb-making facilities.

Washington should insist, at a minimum, that further U.S. financial aid be tied to verifiable and tangible guarantees that Pakistani nuclear materials, bomb-making and enrichment technology components, and scientists, both active and retired, are not made available to other countries -- officially or unofficially.

Pyongyang's nuclear bluff cannot be called until Washington persuades Beijing and Islamabad that nuclear cooperation with North Korea is reckless and cannot be tolerated. Interrupting the supply of nuclear technology, bomb-making materials and extraction chemicals is the best way to curtail North Korea's habitual policy of nuclear blackmail.