German Chancellor Angela Merkel and Berlin Mayor Klaus Wowereit (C) listen to the speech of U.S. President Barack Obama (R) from behind a bulletproof glass at the Brandenburg Gate in Berlin, June 19, 2013. U.S. President Barack Obama will unveil plans for a sharp reduction in nuclear warheads in a landmark speech at the Brandenburg Gate on Wednesday that comes 50 years after John F. Kennedy declared "Ich bin ein Berliner" in a defiant Cold War address. REUTERS/Tobias Schwarz (GERMANY - Tags: POLITICS)