Members of the U.S. Marine Corps listen to President Obama during his visit to Camp Pendleton, Calif., in August. Kevork Djansezian/Getty Images hide caption

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Secretary of State John Kerry on Tuesday as he testified before the House Armed Services Committee. Chip Somodevilla/Getty Images hide caption

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In Washington, D.C., this week, there have been demonstrations both in favor of and against a military strike on targets in Syria. Outside the White House on Monday, supporters of Syrian President Bashar Assad waved a Syrian flag with his face on it. Jewel Samad/AFP/Getty Images hide caption

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Syrian Foreign Minister Walid al-Moualem (left) and Russian Foreign Minister Sergey Lavrov in Moscow on Monday. Yuri Kadobnov /AFP/Getty Images hide caption

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Samantha Power, the U.S. ambassador to the U.N., called military action in Syria legitimate and necessary. Emmanuel Dunand /AFP/Getty Images hide caption

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President Obama on Friday at the G-20 Summit in St. Petersburg, Russia. Kevin Lamarque /Reuters/Landov hide caption

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A U.S. Navy F/A-18F Super Hornet prepares to launch from the aircraft carrier USS Nimitz earlier this week in the Red Sea. The ship is among U.S. military assets in the region. Nathan R. McDonald /UPI/Landov hide caption

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As Secretary of State John Kerry spoke to the House Foreign Affairs Committee on Wednesday, "Code Pink" protesters behind him held up "bloody hands" to express their opposition to the prospect of U.S. military strikes on Syria. Jim Watson /AFP/Getty Images hide caption

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Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey, Secretary of State John Kerry, and Defense Secretary Chuck Hagel testify before the Senate Foreign Relations Committee on Tuesday. Mark Wilson/Getty Images hide caption

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President Obama met with more than a dozen lawmakers, including House Speaker John Boehner and House Minority Leader Nancy Pelosi, at the White House on Tuesday to press his case for a military strike in Syria. Carolyn Kaster/AP hide caption

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Syrian-Kurdish children sit on a bed at the Quru Gusik refugee camp in the Kurdish region of northern Iraq, on Aug. 22. Faced with brutal violence and soaring prices, thousands of Syrian Kurds have poured into Iraq's autonomous Kurdish region. UNICEF has reported that over one million Syrian children live as refugees in other countries. Safin Hamed/AFP/Getty Images hide caption

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At the White House, President Obama and his advisers continue to work to build support in Congress and among allies for striking Syria. Jacquelyn Martin/AP hide caption

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