The only thing that can keep nuclear bombs out of the hands of terrorists is a brand-new science of nuclear forensics.(International Edition; TECHNOLOGY)

In 2007, at the very moment Washington was sitting at the negotiating table with Pyong-Yang to hammer out a nuclear deal, North Korean officials were supplying know-how, equipment and nuclear material to Syria to build a weapons-grade reactor only a few miles from Israel's border. When the news came to light, diplomats and nuclear experts were shocked at Kim Jong Il's duplicity. Israel bombed the Syrian site later that year.

What is Kim Jong Il doing now? The question is foremost on the minds of U.S. national-security officials. Secretary of Defense Robert Gates, when asked recently what keeps him awake at nights, said, "It's the thought of a terrorist ending up ...