The great 19th century Russian playwright Anton Chekhov said it was a rule of the theatrical stage: If a loaded gun appears in the first act, that gun will be fired before the curtain falls. It's a rule of the world stage as well: If rogue states such as North Korea and Iran obtain weapons of mass destruction, we must expect those weapons will be used eventually, with all the death and destruction that implies.

For this reason, preventing the proliferation of nuclear weapons to extreme and irresponsible regimes has long been a priority for American leaders of both political parties. But an effective strategy for keeping such weapons out of despots' clutches has proved elusive.

In 1994, the Clinton administration sat down with North Korean diplomats and cut a deal: The U.S. would provide billions of dollars worth of aid -- massive amounts of food, fuel oil and even two energy-producing nuclear power plants -- in exchange for a promise from Pyongyang to halt nuclear weapons production.

Clinton trusted but did not verify. The North Korean regime was cheating on the deal “before the ink was dry,” in the words of John Bolton, U.S Ambassador to the U.N.

The Bush administration has tried a different approach: multi-lateral diplomacy, endless talks with no one saying anything very persuasive to Kim Jong Il, the vicious and eccentric dictator who has made North Korea into a living hell for most of its citizens.

So what's next? Many Bush critics are, ironically, calling for Bush to go it alone: to agree to another round of direct talks between American and North Korean diplomats. That begs the question: What would we say in such a tête-à-tête? What would be offered? What would be threatened? Without good answers, negotiations can not be productive.

Sanctions against North Korea -- under the auspices of the United Nations -- is the route the Bush administration is now pursuing. To have teeth, they need to include a strict embargo on all military hardware and authorization both to search ships going to and from North Korea and to seize any illicit cargo discovered. That could prevent North Korea from exporting nuclear weapons to terrorists – a useful outcome. But it doesn't go far enough.

What else is necessary? For China to use its considerable leverage to thwart Kim's ambition to head a nuclear-armed state – something it should have done long ago. To persuade China to do the right thing now will require not just diplomatic efforts but diplomatic pressure. Continued...