Nuclear-armed North Korea, and heavily conventionally-armed South Korea, have exchanged fire in one of the sharpest escalations of military violence since the end of the Korean War over 50 years ago. This comes just days after it was revealed that North Korea may have a fully operational, advanced uranium enrichment facility, capable -- as with any uranium enrichment facility in any country -- of enriching uranium to weapons-grade. And just days before that, it was revealed that North Korea is building a new atomic reactor, capable -- as with any reactor in any country -- of generating plutonium that can be extracted via reprocessing for weapons use. In fact, North Korea reprocessed irradiated nuclear fuel from a research reactor to extract the plutonium used in its 2006 and 2009 nuclear weapons test explosions, as well as to fabricate the handful of atomic bombs it is assumed to now possess.