The U.N. Security Council on Wednesday unanimously approved a historic resolution aimed at ending the flow of foreign extremists to the world's conflicts. President Obama thanked the council but warned that "a resolution alone will not be enough." Julie Jacobson/AP hide caption

itoggle caption Julie Jacobson/AP

The chamber of the House of Representatives empties following a joint meeting of Congress with visiting Ukrainian President Petro Poroshenko on Sept. 18. J. Scott Applewhite/AP hide caption

itoggle caption J. Scott Applewhite/AP

President Obama speaks at the U.N. Climate Summit on Tuesday. Discussing America's past, Obama told the group, "We recognize our role in creating this problem." Andrew Burton/Getty Images hide caption

itoggle caption Andrew Burton/Getty Images

President Obama and Vice President Biden on Friday debuted the "It's On Us" campaign to help colleges and universities prevent and respond to sexual assault on campus. J. Scott Applewhite/AP hide caption

itoggle caption J. Scott Applewhite/AP

Ukrainian President Petro Poroshenko, joined by Speaker of the House John Boehner and Vice President Joe Biden, acknowledges lawmakers' applause after addressing a joint meeting of Congress. J. Scott Applewhite/AP hide caption

itoggle caption J. Scott Applewhite/AP

Iranian Foreign Minister Mohammad Javad Zarif speaks during a recent news conference in Rome. Zarif told NPR that the U.S. has been hesitant and contradictory in its approach to dealing with the self-declared Islamic State. Fabio Campana/EPA/Landov hide caption

itoggle caption Fabio Campana/EPA/Landov

House Speaker John Boehner has expressed cautious support for the White House plan. He and other House GOP leaders are backing a measure to authorize the arming and training of moderate Syrian rebels. J. Scott Applewhite/AP hide caption

itoggle caption J. Scott Applewhite/AP

Workers unload medical supplies to fight the Ebola epidemic from a USAID cargo flight in Harbel, Liberia, in August. John Moore/Getty Images hide caption

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Yemeni soldiers hold up their weapons at an area seized from al-Qaida in the southeastern province of Shabwa, Yemen, on May 8. President Obama said Wednesday that U.S. strategy against the so-called Islamic State would be similar to how it targeted militants in Yemen and Somalia. Yemen's Defense Ministry/AP hide caption

itoggle caption Yemen's Defense Ministry/AP

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

itoggle caption Ahmad Al-Rubaye/AFP/Getty Images

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

itoggle caption J. Scott Applewhite/AP

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

itoggle caption Saul Loeb/DPA/Landov

In this image made through a window of the Oval Office, President Obama speaks on the phone to Saudi Arabia's King Abdullah on Wednesday. Charles Dharapak/AP hide caption

itoggle caption Charles Dharapak/AP

Secretary of State John Kerry arrives at Queen Alia International Airport in Amman, Jordan, on Wednesday, ahead of a stop in Iraq. Kerry is hoping to nail down support for a U.S. plan to combat the Islamic State insurgency in Iraq and Syria. Reuters/Landov hide caption

itoggle caption Reuters/Landov

A U.S. military plane lands Aug. 11 on the U.S. Navy aircraft carrier USS George H.W. Bush in the Persian Gulf. U.S. public support of airstrikes against Islamic militants jumped sharply, according to a new poll, as President Obama prepares a strategy. Hasan Jamali/AP hide caption

itoggle caption Hasan Jamali/AP