Fighters from the Islamic State group parade in their northern Syrian stronghold, Raqqa. Uncredited/AP/Raqqa Media Center hide caption

itoggle caption Uncredited/AP/Raqqa Media Center

This still image was made from video released by the U.S. military on Tuesday that shows a building hit by a U.S. airstrike in Tall Al Qitar, Syria. The U.S. is describing the bombing campaign in Syria and Iraq as a counterterrorism operation and not a war. U.S. Central Command/AP hide caption

itoggle caption U.S. Central Command/AP

Thousands of Syrians enter Turkey at Yumurtalik crossing gate near Suruc on Tuesday. The United Nations High Commissioner for Refugees has warned of a growing refugee crisis. Burhan Ozbilici/AP hide caption

itoggle caption Burhan Ozbilici/AP

Lt. Gen. William C. Mayville Jr., Joint Staff Director of Operations, speaks about airstrikes in Syria during a briefing at the Pentagon yesterday. Brendan Smialowski/AFP/Getty Images hide caption

itoggle caption Brendan Smialowski/AFP/Getty Images

Iraqi Kurdish peshmerga fighters take up positions around the town of Gwer in northern Iraq on Sept. 18. The Kurdish militia is aligned with the U.S. in the battle against the Islamic State. Mohamed Messara/EPA/Landov hide caption

itoggle caption Mohamed Messara/EPA/Landov

Syrian Kurds with their livestock wait behind a border fence near the southeastern town of Suruc in Sanliurfa province on Monday. Some 100,000 Kurds have fled from Syria into Turkey amid intense fighting between peshmerga forces and ISIS. Murad Sezer/Reuters/Landov hide caption

itoggle caption Murad Sezer/Reuters/Landov

A Syrian family waits near the Turkish-Syrian border after entering Turkey near the town of Sanliurfa Sunday. An estimated 70,000 Syrian Kurds have fled the extremist group the Islamic State this weekend. Ulas Yunus Tosun/EPA /LANDOV hide caption

itoggle caption Ulas Yunus Tosun/EPA /LANDOV

Nicaragua's Contra rebels in 1990. The U.S. backed the Contras in the 1980s, which led to the ouster of the leftist Sandinista leadership. But the U.S. aid violated American law and contributed to the biggest scandal of President Reagan's administration. Michael Stravato/AP hide caption

itoggle caption Michael Stravato/AP

Prime Minister Ahmet Davutoglu, center, poses with dozens of freed Turkish hostages at the Esenboga Airport in Ankara Saturday. The group was held by militants in northern Iraq for more than three months. Adem Altan/AFP/Getty Images hide caption

itoggle caption Adem Altan/AFP/Getty Images

A remote camera screen grab provided by the French army shows two Rafale jet fighters flying over Iraq on Friday. French President Francois Hollande announced that the fighters had carried out their first airstrikes in northern Iraq. AP hide caption

itoggle caption AP

Syrian rebel fighters in the northern city of Aleppo in August. The Obama administration has been vetting rebel groups and decided that more than a dozen are moderate enough to arm. Zein al-Rifai/AFP/Getty Images hide caption

itoggle caption Zein al-Rifai/AFP/Getty Images

This image, posted on a militant website, shows an Islamic State fighter waving a flag from a captured government fighter jet in Raqqa, Syria. The Islamic State captured the city in northeastern Syria last year and it has effectively served as its capital. Uncredited/AP hide caption

itoggle caption Uncredited/AP

House Speaker John Boehner, R-Ohio, leaves after a news conference Thursday on Capitol Hill in Washington. Boehner responded positively to the proposals from President Obama about confronting Islamist militants in Iraq and Syria. J. Scott Applewhite/AP hide caption

itoggle caption J. Scott Applewhite/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

President Obama addresses the nation from Cross Hall in the White House on Wednesday. Opening a new military front in the Middle East, Obama authorized U.S. airstrikes inside Syria for the first time, along with expanded strikes in Iraq as part of a broad mission to root out violent Islamic State militants. Saul Loeb/AP hide caption

itoggle caption Saul Loeb/AP

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

itoggle caption Saul Loeb/AFP/Getty Images