More than 50 world leaders are attending a nuclear security summit in Washington this week. But Vladimir Putin is a no-show. And, as if on cue, North Korea fired a ballistic missile on Friday.
These biannual nuclear summits, aimed at locking down fissile material worldwide that could be used for doomsday weapons, were proposed by President Obama back in 2009, barely two months into his presidency.
"We must insure that terrorists never acquire a nuclear weapon," he declared, calling such a scenario "the most immediate and extreme threat to global security."