THE HAGUE, NETHERLANDS - MARCH 24:  King Willem-Alexander of The Netherlands and Queen Maxima of The Netherlands greet U.S. President Barack Obama at the Royal Palace Huis ten Bosch on March 24, 2014 in The Hague, Netherlands. The Nuclear Security Summit, held March 24-25, will be attended by world leaders and is aimed at preventing nuclear terrorism.  (Photo by Koen Van Weel - Pool/Getty Images)