DANGEROUS LIAISONS.

The article reports on a company's nuclear secrets leaking to Iran and North Korea and the successive fallouts. Three decades ago, a brilliant young Pakistani metallurgist named Abdul Qadeer Khan managed to steal highly classified nuclear secrets while working in Amsterdam, Netherlands. It was a theft that first shook Pakistan's Chagai Hills test site, and ultimately the rest of the planet. Working for a firm that contracted with Urenco, a Dutch-German-British company that provides uranium-enrichment services to nuclear power plants, Khan had access to Urenco's secret blueprints and manuals. He learned how to enrich uranium in centrifuges to make fuel for nuclear power plants but also for weapons. Last year, Khan confessed to selling his nuclear know-how not only to Pakistan but also to North Korea, Libya, and Iran. Khan and the global nuclear black market he spawned are directly responsible for the current standoff over Iran's plans to build a centrifuge uranium-enrichment plant. Now Pakistan has put Khan under house arrest, but the company that allowed the world's worst nuclear-security leaks is prospering. INSETS: FUELING THE FIRE;SPEAK OUT FOR SAFE ENERGY.