There's been much talk in the past few weeks about failures to connect the dots to find a pattern that might have alerted us to the terrorist plot of Sept. 11. Recently I visited a dot in a more fearsome pattern configuring the virtual certainty of mass terror involving nuclear, chemical or biological weapons if the international coalition does not extend its efforts from hunting al Qaeda-like cells to locking up the ingredients of mass destruction. The dot I visited was at Mayak, east of the Ural Mountains in Asian Russia. There, a huge concrete sarcophagus rises from the landscape. Its purpose is to entomb some 20,000 nuclear bombs' worth of plutonium and highly enriched uranium. Ashton Carter on protecting former Soviet nukes. | 
