U.S. Secretary of Defense Chuck Hagel (L) welcomes German Defense Minister Ursula von der Leyen before their meeting at the Pentagon in Washington June 19, 2014. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

U.S. Secretary of Defense Chuck Hagel (L) welcomes German Defense Minister Ursula von der Leyen before their meeting at the Pentagon in Washington June 19, 2014. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

U.S. Secretary of Defense Chuck Hagel welcomes German Defense Minister Ursula von der Leyen before their meeting at the Pentagon in Washington June 19, 2014. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

U.S. Secretary of Defense Chuck Hagel (L) welcomes German Defense Minister Ursula von der Leyen before their meeting at the Pentagon in Washington June 19, 2014. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

U.S. Secretary of Defense Chuck Hagel (L) welcomes German Defense Minister Ursula von der Leyen before their meeting at the Pentagon in Washington June 19, 2014. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

U.S. Secretary of Defense Chuck Hagel (L) welcomes German Defense Minister Ursula von der Leyen before their meeting at the Pentagon in Washington June 19, 2014. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

U.S. Secretary of Defense Chuck Hagel kisses German Defense Minister Ursula von der Leyen before their meeting at the Pentagon in Washington June 19, 2014. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

A U.S. Marine, who is part of a military honor guard, takes his position before a welcoming ceremony for German Defense Minister Thomas de Maiziere, by U.S. Defense Secretary Chuck Hagel, at the Pentagon in Washington April 30, 2013. REUTERS/Gary Cameron (UNITED STATES - Tags: MILITARY POLITICS) 

Members of the U.S. military honor guard take their positions before a welcoming ceremony for German Defense Minister Thomas de Maiziere, by U.S. Defense Secretary Chuck Hagel, at the Pentagon in Washington April 30, 2013. REUTERS/Gary Cameron (UNITED STATES - Tags: MILITARY POLITICS) 

U.S. Defense Secretary Chuck Hagel welcomes German Defense Minister Thomas de Maiziere (R) to the Pentagon in Washington April 30, 2013. REUTERS/Gary Cameron (UNITED STATES - Tags: MILITARY POLITICS) 

U.S. Defense Secretary Chuck Hagel welcomes German Defense Minister Thomas de Maiziere (front) to the Pentagon in Washington April 30, 2013. REUTERS/Gary Cameron (UNITED STATES - Tags: MILITARY POLITICS) 

U.S. Defense Secretary Chuck Hagel (L) welcomes German Defense Minister Thomas de Maiziere to the Pentagon in Washington April 30, 2013. REUTERS/Gary Cameron (UNITED STATES - Tags: MILITARY POLITICS) 

U.S. Defense Secretary Chuck Hagel (L) welcomes German Defense Minister Thomas de Maiziere to the Pentagon in Washington April 30, 2013. REUTERS/Gary Cameron (UNITED STATES - Tags: MILITARY POLITICS) 

U.S. Defense Secretary Chuck Hagel (L) welcomes German Defense Minister Thomas de Maiziere to the Pentagon in Washington April 30, 2013. REUTERS/Gary Cameron (UNITED STATES - Tags: MILITARY POLITICS) 

A KC-135 tanker aircraft is pictured during a mid-air refueling of U.S. Secretary of Defense Chuck Hagel's E-4B, a militarized version of a Boeing 747, as he returns from Ramstein Airbase in Germany to Andrews Air Force Base near Washington, over Newfoundland March 11, 2013. Hagel returned to Washington from his first visit to Afghanistan as Secretary of Defense on Monday. According to the crew of the aircraft, which serves as the National Airborne Operations Center for the president, secretary of defense and the Joint Chiefs of Staff, 60,000lbs of jet fuel was transferred in the operation at an altitude of 24,000 feet. The aircraft requires refueling on long legs due to its heavy weight. REUTERS/Jason Reed (CANADA - Tags: MILITARY POLITICS TRANSPORT) 

A "Silver Bullet" airstream trailer (C) carrying U.S. Secretary of Defense Chuck Hagel is pictured inside a U.S. Air Force C-17 aircraft transporting him and his staff from Kabul to Ramstein Airbase in Germany, March 11, 2013. Hagel returned to Washington from his first visit to Afghanistan as Secretary of Defense on Monday. REUTERS/Jason Reed (AFGHANISTAN - Tags: MILITARY POLITICS TRANSPORT TPX IMAGES OF THE DAY) 

Former U.S. Republican Senator Chuck Hagel (C) chats with Chancellor of Germany Angela Merkel (R) as she arrives to receive the Eric M. Warburg Award from the Atlantik-Brucke Group during a ceremony at the Library of Congress in Washington, June 25, 2009. The Warburg Award, given by the the Atlantik-Brucke Group to promote transatlantic understanding and cooperation, is named for a member of a prominent German-Jewish banking family who fled Nazi Germany in 1938 and found refuge in the U.S. REUTERS/Jonathan Ernst (UNITED STATES POLITICS) 

Chancellor of Germany Angela Merkel (R) is applauded by Airbus CEO Thomas Enders (from L-2nd R), former US Senator Chuck Hagel, Walther Leisler Kiep and Beate Lindemann as she receives the Eric M. Warburg Award from the Atlantik-Brucke Group during a ceremony at the Library of Congress in Washington, June 25, 2009. The Warburg Award, given by the the Atlantik-Brucke Group to honor transatlantic understanding and cooperation, is named for a member of a prominent German-Jewish banking family who fled Nazi Germany in 1938 and found refuge in the US. REUTERS/Jonathan Ernst (UNITED STATES POLITICS)