U.S. President Barack Obama shakes hands with Vice President Joe Biden (4th R), Secretary of State John Kerry (2nd R) and Defense Secretary Chuck Hagel (R) after his statement on legislation sent to Congress to authorize the use of military force against the Islamic State, from the Roosevelt Room at the White House in Washington February 11, 2015. Obama said on Wednesday that he consulted Republicans and Democrats in the U.S. Congress before submitting a request for authorization of military force against Islamic State. REUTERS/Jonathan Ernst (UNITED STATES - Tags: POLITICS MILITARY CONFLICT) 

U.S. President Barack Obama is flanked by Vice President Joe Biden (L), Secretary of State John Kerry (2nd R) and Defense Secretary Chuck Hagel (R) as he delivers a statement on legislation sent to Congress to authorize the use of military force against the Islamic State, from the Roosevelt Room at the White House in Washington February 11, 2015. Obama asked Congress on Wednesday to authorize military force against Islamic State that would bar any large-scale invasion by U.S. ground troops and limit operations to three years. REUTERS/Jonathan Ernst (UNITED STATES - Tags: POLITICS MILITARY CONFLICT) 

United States Secretary of Defense Chuck Hagel and Prime Minister of Romania Victor Ponta (L) listen to their respective national anthems to the Pentagon during an honor cordon in Washington February 11, 2015. REUTERS/Gary Cameron (UNITED STATES - Tags: MILITARY POLITICS) 

U.S. President Barack Obama is flanked by Vice President Joe Biden (L), Secretary of State John Kerry (2nd R) and Defense Secretary Chuck Hagel (R) as he delivers a statement on legislation sent to Congress to authorize the use of military force against the Islamic State, from the Roosevelt Room at the White House in Washington February 11, 2015. Obama asked Congress on Wednesday to authorize military force against Islamic State that would bar any large-scale invasion by U.S. ground troops and limit operations to three years. REUTERS/Jonathan Ernst (UNITED STATES - Tags: POLITICS MILITARY CONFLICT) 

United States Secretary of Defense Chuck Hagel welcomes Prime Minister of Romania Victor Ponta (not pictured) to the Pentagon during an honor cordon in Washington February 11, 2015. REUTERS/Gary Cameron (UNITED STATES - Tags: MILITARY POLITICS) 

U.S. President Barack Obama is flanked by Vice President Joe Biden (L), Secretary of State John Kerry (2nd R) and Defense Secretary Chuck Hagel (R) as he delivers a statement on legislation sent to Congress to authorize the use of military force against the Islamic State, from the Roosevelt Room at the White House in Washington February 11, 2015. Obama asked Congress on Wednesday to authorize military force against Islamic State that would bar any large-scale invasion by U.S. ground troops and limit operations to three years. REUTERS/Jonathan Ernst (UNITED STATES - Tags: POLITICS MILITARY CONFLICT TPX IMAGES OF THE DAY) 

U.S. President Barack Obama is flanked by Secretary of State John Kerry (2nd R) and Defense Secretary Chuck Hagel (R) as he delivers a statement on legislation sent to Congress to authorize the use of military force against the Islamic State, from the Roosevelt Room at the White House in Washington February 11, 2015. Obama asked Congress on Wednesday to authorize military force against Islamic State that would bar any large-scale invasion by U.S. ground troops and limit operations to three years. REUTERS/Jonathan Ernst (UNITED STATES - Tags: POLITICS MILITARY CONFLICT) 

United States Secretary of Defense Chuck Hagel and Prime Minister of Romania Victor Ponta (L) listen to their respective national anthems at the Pentagon during an honor cordon in Washington February 11, 2015. REUTERS/Gary Cameron (UNITED STATES - Tags: MILITARY POLITICS) 

United States Secretary of Defense Chuck Hagel welcomes Prime Minister of Romania Victor Ponta (C) to the Pentagon during an honor cordon in Washington February 11, 2015. REUTERS/Gary Cameron (UNITED STATES - Tags: MILITARY POLITICS) 

United States Secretary of Defense Chuck Hagel (2nd L) welcomes Prime Minister of Romania Victor Ponta to the Pentagon during an honor cordon in Washington February 11, 2015. REUTERS/Gary Cameron (UNITED STATES - Tags: MILITARY POLITICS) 

United States Secretary of Defense Chuck Hagel (R) welcomes Prime Minister of Romania Victor Ponta to the Pentagon during an honor cordon in Washington February 11, 2015. REUTERS/Gary Cameron (UNITED STATES - Tags: MILITARY POLITICS) 

United States Secretary of Defense Chuck Hagel (L) welcomes Prime Minister of Romania Victor Ponta to the Pentagon during an honor cordon in Washington February 11, 2015. REUTERS/Gary Cameron (UNITED STATES - Tags: MILITARY POLITICS) 

Britain's Defence Secretary Michael Fallon listens to U.S. Secretary of Defense Chuck Hagel (R) during a NATO defence ministers meeting at the Alliance headquarters in Brussels February 5, 2015. REUTERS/Francois Lenoir (BELGIUM - Tags: POLITICS MILITARY) 

Britain's Defence Secretary Michael Fallon talks to U.S. Secretary of Defense Chuck Hagel (R) during a NATO defence ministers meeting at the Alliance headquarters in Brussels February 5, 2015. REUTERS/Francois Lenoir (BELGIUM - Tags: POLITICS MILITARY) 

(L-R) NATO Secretary General Jens Stoltenberg greets U.S. Secretary of Defense Chuck Hagel next to Britain's Defence Secretary Michael Fallon as they pose for a family photo during a NATO defence ministers meeting at the Alliance headquarters in Brussels February 5, 2015. REUTERS/Francois Lenoir (BELGIUM - Tags: POLITICS MILITARY) 

U.S. Secretary of Defense Chuck Hagel greets Britain's Defence Secretary Michael Fallon (R) as they pose for a family photo during a NATO defence ministers meeting at the Alliance headquarters in Brussels February 5, 2015. REUTERS/Francois Lenoir (BELGIUM - Tags: POLITICS MILITARY) 

U.S. Defense Secretary Chuck Hagel addresses a news conference during a NATO defence ministers meeting at the Alliance headquarters in Brussels February 5, 2015. REUTERS/Francois Lenoir (BELGIUM - Tags: POLITICS MILITARY) 

U.S. Defense Secretary Chuck Hagel addresses a news conference during a NATO defence ministers meeting at the Alliance headquarters in Brussels February 5, 2015. REUTERS/Francois Lenoir (BELGIUM - Tags: POLITICS MILITARY) 

U.S. Defense Secretary Chuck Hagel addresses a news conference during a NATO defence ministers meeting at the Alliance headquarters in Brussels February 5, 2015. REUTERS/Francois Lenoir (BELGIUM - Tags: POLITICS MILITARY) 

U.S. Defense Secretary Chuck Hagel listens to Portugal's Defence Minister Jose Pedro Aguiar-Branco (R) during a NATO-Georgia defence ministers meeting at the Alliance headquarters in Brussels February 5, 2015. NATO defence ministers met on Thursday to sign off on a network of command centres in eastern Europe to rapidly reinforce the region in the event of any threat from Russia, as well as a new regional headquarters and a bigger rapid reaction force. REUTERS/Francois Lenoir (BELGIUM - Tags: POLITICS MILITARY) 

(L-R) Norway's Defence Minister Ine Marie Eriksen, U.S. Defense Secretary Chuck Hagel and Polish Defence Minister Tomasz Siemoniak attend a NATO-Georgia defence ministers meeting at the Alliance headquarters in Brussels February 5, 2015. NATO defence ministers met on Thursday to sign off on a network of command centres in eastern Europe to rapidly reinforce the region in the event of any threat from Russia, as well as a new regional headquarters and a bigger rapid reaction force. REUTERS/Francois Lenoir (BELGIUM - Tags: POLITICS MILITARY) 

U.S. President Barack Obama meets members of his Cabinet at the White House in Washington February 3, 2015. Flanking Obama are Secretary of State John Kerry (L) and Secretary of Defense Chuck Hagel.
REUTERS/Kevin Lamarque (UNITED STATES - Tags: POLITICS) 

U.S. President Barack Obama meets members of his Cabinet at the White House in Washington February 3, 2015. Flanking Obama are Secretary of State John Kerry (L) and Secretary of Defense Chuck Hagel.
REUTERS/Kevin Lamarque (UNITED STATES - Tags: POLITICS) 

U.S. President Barack Obama and Vice President Joe Biden (R) arrive at the armed services farewell in honor of Defense Secretary Chuck Hagel at Joint Base Myer-Henderson Hall in Virginia, January 28, 2015. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

Joint Chiefs of Staff Gen. Martin Dempsey holds a program during the armed services farewell in honor of Defense Secretary Chuck Hagel at Joint Base Myer-Henderson Hall in Virginia, January 28, 2015. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

U.S. President Barack Obama stands up to deliver remarks at the armed services farewell in honor of Defense Secretary Chuck Hagel (next to Obama) at Joint Base Myer-Henderson Hall in Virginia, January 28, 2015. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

U.S. President Barack Obama walks to deliver remarks at the armed services farewell in honor of Defense Secretary Chuck Hagel at Joint Base Myer-Henderson Hall in Virginia, January 28, 2015. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

Outgoing U.S. Defense Secretary Chuck Hagel waves to the troops during a farewell ceremony at Joint Base Myer-Henderson Hall in Virginia, January 28, 2015. REUTERS/Yuri Gripas (UNITED STATES - Tags: MILITARY POLITICS TPX IMAGES OF THE DAY) 

U.S. President Barack Obama delivers remarks at the armed services farewell in honor of Defense Secretary Chuck Hagel at Joint Base Myer-Henderson Hall in Virginia, January 28, 2015. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

Outgoing U.S. Defense Secretary Chuck Hagel (R) reviews troops during a farewell ceremony at Joint Base Myer-Henderson Hall in Virginia, January 28, 2015. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

Outgoing U.S. Defense Secretary Chuck Hagel walks during a farewell ceremony at Joint Base Myer-Henderson Hall in Virginia, January 28, 2015. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY TPX IMAGES OF THE DAY) 

Outgoing U.S. Defense Secretary Chuck Hagel walks during a farewell ceremony at Joint Base Myer-Henderson Hall in Virginia, January 28, 2015. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

Fife and Drum Corps honor guards march at the armed services farewell in honor of Defense Secretary Chuck Hagel at Joint Base Myer-Henderson Hall in Virginia, January 28, 2015. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

U.S. President Barack Obama delivers remarks at the armed services farewell in honor of Defense Secretary Chuck Hagel at Joint Base Myer-Henderson Hall in Virginia, January 28, 2015. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

U.S. President Barack Obama delivers remarks at the armed services farewell in honor of Defense Secretary Chuck Hagel at Joint Base Myer-Henderson Hall in Virginia, January 28, 2015. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

U.S. President Barack Obama (C) and Vice President Joe Biden (R) attend a farewell ceremony for Defense Secretary Chuck Hagel (L) at Joint Base Myer-Henderson Hall in Virginia, January 28, 2015. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

Outgoing U.S. Defense Secretary Chuck Hagel (L) looks at President Barack Obama during a farewell ceremony at Joint Base Myer-Henderson Hall in Virginia, January 28, 2015. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

(L-R) Outgoing Defense Secretary Chuck Hagel, U.S. President Barack Obama, Vice President Joe Biden and Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey attend a farewell ceremony for Hagel, at Joint Base Myer-Henderson Hall in Virginia, January 28, 2015. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

(L-R) Outgoing Defense Secretary Chuck Hagel, U.S. President Barack Obama, Vice President Joe Biden and Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey attend a farewell ceremony for Hagel, at Joint Base Myer-Henderson Hall in Virginia, January 28, 2015. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

U.S. President Barack Obama (C) and Vice President Joe Biden (R) attend a farewell ceremony for Defense Secretary Chuck Hagel (L) at Joint Base Myer-Henderson Hall in Virginia, January 28, 2015. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

Outgoing U.S. Defense Secretary Chuck Hagel speaks during a farewell ceremony at Joint Base Myer-Henderson Hall in Virginia, January 28, 2015. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

U.S. President Barack Obama (L) hugs outgoing Defense Secretary Chuck Hagel during a farewell ceremony at Joint Base Myer-Henderson Hall in Virginia, January 28, 2015. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

U.S. President Barack Obama (L) hugs outgoing Defense Secretary Chuck Hagel during a farewell ceremony at Joint Base Myer-Henderson Hall in Virginia, January 28, 2015. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

U.S. President Barack Obama (L) hugs outgoing Defense Secretary Chuck Hagel during a farewell ceremony at Joint Base Myer-Henderson Hall in Virginia, January 28, 2015. REUTERS/Yuri Gripas (UNITED STATES - Tags: MILITARY POLITICS TPX IMAGES OF THE DAY) 

U.S. President Barack Obama (L) greets outgoing U.S. Defense Secretary Chuck Hagel during a farewell ceremony at Joint Base Myer-Henderson Hall in Virginia, January 28, 2015. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY TPX IMAGES OF THE DAY) 

U.S. President Barack Obama (L) hugs outgoing U.S. Defense Secretary Chuck Hagel during a farewell ceremony at Joint Base Myer-Henderson Hall in Virginia, January 28, 2015. REUTERS/Yuri Gripas (UNITED STATES - Tags: POLITICS MILITARY) 

U.S. Secretary of Defense Chuck Hagel pauses during a news conference at the Pentagon in Washington, January 22, 2015. Iraqi Prime Minister Haidar al-Abadi's criticism of the pace of support from the U.S.-led coalition is not helpful, Hagel said on Thursday, noting expedited U.S. arms shipments and fresh coalition efforts to support Iraq. REUTERS/Larry Downing (UNITED STATES - Tags: POLITICS MILITARY TPX IMAGES OF THE DAY) 

U.S. Secretary of Defense Chuck Hagel walks out after a news conference at the Pentagon in Washington, January 22, 2015. Iraqi Prime Minister Haidar al-Abadi's criticism of the pace of support from the U.S.-led coalition is not helpful, Hagel said on Thursday, noting expedited U.S. arms shipments and fresh coalition efforts to support Iraq. REUTERS/Larry Downing (UNITED STATES - Tags: POLITICS MILITARY) 

U.S. Secretary of Defense Chuck Hagel waves at the end of a news conference at the Pentagon in Washington, January 22, 2015. Iraqi Prime Minister Haidar al-Abadi's criticism of the pace of support from the U.S.-led coalition is not helpful, Hagel said on Thursday, noting expedited U.S. arms shipments and fresh coalition efforts to support Iraq. REUTERS/Larry Downing (UNITED STATES - Tags: POLITICS MILITARY) 

U.S. Secretary of Defense Chuck Hagel talks during a news conference at the Pentagon in Washington, January 22, 2015. Iraqi Prime Minister Haidar al-Abadi's criticism of the pace of support from the U.S.-led coalition is not helpful, Hagel said on Thursday, noting expedited U.S. arms shipments and fresh coalition efforts to support Iraq. REUTERS/Larry Downing (UNITED STATES - Tags: POLITICS MILITARY) 

U.S. Secretary of Defense Chuck Hagel speaks during a news conference at the Pentagon in Washington, January 22, 2015. Iraqi Prime Minister Haidar al-Abadi's criticism of the pace of support from the U.S.-led coalition is not helpful, U.S. Defense Secretary Chuck Hagel said on Thursday, noting expedited U.S. arms shipments and fresh coalition efforts to support Iraq. REUTERS/Larry Downing (UNITED STATES - Tags: POLITICS MILITARY) 

U.S. Secretary of Defense Chuck Hagel gestures during his news conference at the Pentagon in Washington, January 22, 2015. REUTERS/Larry Downing (UNITED STATES - Tags: POLITICS MILITARY) 

U.S. Secretary of Defense Chuck Hagel pauses during a news conference at the Pentagon in Washington, January 22, 2015. REUTERS/Larry Downing (UNITED STATES - Tags: POLITICS MILITARY) 

U.S. Secretary of Defense Chuck Hagel gestures during a news conference at the Pentagon in Washington, January 22, 2015. REUTERS/Larry Downing (UNITED STATES - Tags: POLITICS MILITARY) 

U.S. President Barack Obama (L) greets outgoing U.S. Secretary of Defense Chuck Hagel (C), as Secretary of Treasury Jacob Lew watches after Obama delivered his State of the Union address to a joint session of Congress on Capitol Hill in Washington, January 20, 2015. REUTERS/Mandel Ngan/Pool (UNITED STATES - Tags: POLITICS) 

U.S. President Barack Obama (L) greets outgoing U.S. Secretary of Defense Chuck Hagel (R) and Attorney General Eric Holder (C) after Obama delivered delivered his State of the Union address to a joint session of Congress on Capitol Hill in Washington, January 20, 2015. REUTERS/Mandel Ngan/Pool (UNITED STATES - Tags: POLITICS) 

U.S. President Barack Obama (L) shakes hands with outgoing U.S. Secretary of Defense Chuck Hagel (R) after Obama delivered delivered his State of the Union address to a joint session of Congress on Capitol Hill in Washington, January 20, 2015. REUTERS/Mandel Ngan/Pool (UNITED STATES - Tags: POLITICS) 

U.S. Defense Secretary Chuck Hagel (bottom, L) and Secretary of State John Kerry arrive to attend U.S. President Barack Obama's State of the Union address to a joint session of the U.S. Congress on Capitol Hill in Washington, January 20, 2015. REUTERS/Jonathan Ernst (UNITED STATES - Tags: POLITICS)

Iraq's Mamoun Tower is seen from U.S. Secretary of Defense Chuck Hagel's helicopter, as it flies over the city, in Baghdad, December 9, 2014. U.S. Defense Secretary Chuck Hagel arrived in Baghdad on Tuesday as the United States expands its presence and touts progress against Islamic State militants four months after starting a campaign of air strikes in Iraq. REUTERS/Mark Wilson/Pool (IRAQ - Tags: POLITICS CITYSCAPE BUSINESS TELECOMS) 

The uncompleted al-Rahman mosque is seen from a distance from U.S. Secretary of Defense Chuck Hagel's helicopter, as it flies over the city, in Baghdad, December 9, 2014. U.S. Defense Secretary Chuck Hagel arrived in Baghdad on Tuesday as the United States expands its presence and touts progress against Islamic State militants four months after starting a campaign of air strikes in Iraq. REUTERS/Mark Wilson/Pool (IRAQ - Tags: POLITICS CIVIL UNREST RELIGION BUSINESS CONSTRUCTION CITYSCAPE)