Foreign Policy Staff Wrter Josh Rogin talked about the nuclear security summit, taking place on April 12 and 13. Over 40 world leaders will meet in Washington for a nuclear summit to find solutions to improve global nuclear security. Today, Vice President Joe Biden will host a luncheon with attendees at his residence and the President will hold a dinner for heads of state. Last week, Pres. Obama and Russian Pres. Medvedev signed a new Strategic Arms Reduction Treaty in an effort to sway other nations to limit their weapons cache.