Members of the anti-war activist group CodePink interrupt a Senate Armed Services Committee hearing with Defense Secretary Chuck Hagel (left) and Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff. J. Scott Applewhite/AP hide caption

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French President Francois Hollande (right) and Iraqi President Fuad Masum attend the Conference for Peace and Security in Iraq at the Ministry of Foreign Affairs in Paris on Monday. The two leaders were among those urging quick action against Islamic State militants. David Silpa/UPI/Landov hide caption

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Iraqi troops in Anbar province in June. It's unclear whether Sunnis will join the U.S. in the fight against the Islamic State. AFP/Getty Images hide caption

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President Obama's plan to degrade and destroy the Islamic state poses a challenge for members of his own party, who have traditionally provided the anti-war voices in Congress. Saul Loeb/AP hide caption

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Millions watched President Obama's prime-time address this week, like these patrons of a San Francisco nail salon. But whether Americans will support his plan remains unclear. Justin Sullivan/Getty Images hide caption

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A young Iraqi on Thursday stands amid the debris of a double car bomb attack in Baghdad. There was no immediate claim of responsibility. President Obama's plan to attack Islamic State militants in Iraq and Syria will require help from partners on the ground in both countries. Ahmad Al-Rubaye/AFP/Getty Images hide caption

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House Speaker John Boehner, R-Ohio, on Capitol Hill on Thursday. Boehner says Congress stands ready to work with the president on the threat from Islamic State militants. J. Scott Applewhite/AP hide caption

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President Obama, first lady Michelle Obama, Vice President Joe Biden and others observe a moment of silence on the South Lawn of the White House on Thursday to mark the 13th anniversary of the Sept. 11 attacks. Charles Dharapak/AP hide caption

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President Obama delivers a prime-time address from the Cross Hall of the White House on Wednesday. He pledged to lead a broad coalition against the Islamic State insurgents and vowed to target the terrorist group with airstrikes "wherever they exist." Saul Loeb/DPA/Landov hide caption

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President Obama has been wary of open-ended military commitments in the Middle East. But the president, shown speaking in Estonia on Sept. 3, now appears likely to expand the current bombing campaign against the Islamic State. Saul Loeb/AFP/Getty Images hide caption

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