North Korea's penchant for behaving badly never ceases to amaze.

The U.N.'s International Atomic Energy Agency (IAEA) says it appears that North Korea sold Libya nearly two tons of uranium for use in its (now defunct) nuclear-weapons program.

You have to wonder: Isn't there any way to get North Korea's captain of catastrophe, Kim Jong Il, under control? The answer, surprisingly, may lie right here in Japan.

Last week, North Korea ransomed the children of kidnap victims back to Japan - and cashed in big. Pyongyang raked in 250,000 tons of rice and $10 million in medical supplies from Japan in exchange for releasing five North Korean-born children of four former Japanese abductees, kidnapped by North Korean agents during the 1970s and 1980s.

Last October, Kim allowed the Japanese adults to leave North Korea, but wouldn't let their children go along, undoubtedly holding them for the right price. (U.S. Army Sgt. Charles Jenkins, who defected in 1965 and married of one of the now-released Japanese abductees, decided to stay behind with his two daughters rather than face extradition to the U.S. for charges of desertion and treason.)

At least 10 other Japanese abductee cases remain unresolved. North Korea insists these Japanese a) died in North Korea or b) never entered the Hermit Kingdom. Some speculate that these 10 were used as instructors in North Korean spy schools, so their release might expose North Korean agents worldwide. If that's the case, North Korea will hold them back.

Japanese family groups say these 10 cases are just the tip of the iceberg. They claim North Korean agents may have kidnapped as many as 400 Japanese citizens.

But Japanese Prime Minister Junichiro Koizumi has more on his mind than kidnap victims when dealing with Kim Jong Il. During his trip to Pyongyang last weekend to gain the children's release, Koizumi also pressed Kim to give up his nuclear-weapons program.

Though unsuccessful, the effort was timely. Reports this week indicate IAEA experts have uncovered hard evidence that North Korea shuffled as much as two tons of uranium hexafluoride (UF6, a basic building block in developing nuclear weapons) to Libya in 2001.

If confirmed, this would be the first known case of North Korea selling nuke ingredients abroad. (It's already the world's most prodigious proliferator of ballistic missiles to Iran, Syria, Pakistan and others.)

Libya's program is being dismantled, but the white-hot questions are: 1) To whom else (e.g., terrorists) did North Korea sell nuclear material? 2) What is the real breadth and width of North Korea's nuclear programs? It may be much larger than the two or three once believed.

Conventional wisdom says that China is the country most able to get Pyongyang to deal for its nuclear program. But Japan may come in a close second and could provide the leverage needed to reel in the ornery North Koreans.

Though the Japanese are not wont to do so, Tokyo could put the squeeze on resource-starved Pyongyang through economic sanctions and diplomatic holdouts. (Washington has little or nothing left to sanction.)

• The Japanese could bar North Korean ships from making port calls in Japan, preventing the movement of modern goods and technology from Japan - a lifeline to North Korea's struggling economy.
• Japan could cut off the cash remittances sent home by the 150,000 North Korean citizens who live in Japan. These expatriates funnel hundreds of million of dollars a year in cold, hard cash to North Korea's needy elite.
• Japan could put down firm markers on what North Korea must do before diplomatic relations between the two countries can be normalized. And North Korea has a huge incentive to pursue normalization: Tokyo is likely to provide $10 billion in reparations for its Korean occupation (1910-1945).

Since the end World War II, the Japanese have (understandably) not been much for taking the hard line in international politics. But the stakes posed by North Korea's nuclear program to Northeast Asian security - and beyond - are so huge, it's time for Tokyo to play hardball with Kim's Korea.

Peter Brookes ([email protected]) is a Heritage Foundation senior fellow.