Prime Minister of Pakistan Yusuf Raza Gilani (C) arrives ahead of an upcoming nuclear security summit organised by U.S. President Barack Obama in Washington, at Andrews Air Force Base, Maryland April 11, 2010. Pakistan will confront its reputation as a proliferator head-on this week when Gilani addresses a global summit in Washington aimed at keeping nuclear weapons out of the hands of terrorists. REUTERS/Jonathan Ernst (UNITED STATES - Tags: POLITICS ENERGY)