North Korea isn't done thumbing its nose at the world, and is now preparing to launch a third nuclear weapons test, a senior source tells Reuters. When asked if North Korea was planning another nuclear test, following its much-condemned 2006 and 2009 demonstrations, the official replied, "Soon. Preparations are almost complete." Observers say it may be Pyongyang's first test using highly enriched uranium, a worrying prospect, since it would mean North Korea could more easily produce warheads for long-range missiles. (More North Korea stories.)