Gen. David Petraeus greets an Iraqi man at a tea shop in Baghdad in 2007. In 2011, Petraeus left the Army to become CIA director. He resigned Friday, citing an extramarital affair. Chris Hondros/Getty Images hide caption

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The candidates agreed to 21 pages of debate rules, but whether they obey them is another story. Saul Loeb/AFP/Getty Images hide caption

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Sgt. Michael Clark and his fiancee, Kaitlin Forant, hold their son, Michael Clark Jr. It took time for the 18-month-old to recognize his father after Clark's deployment. Tom Dreisbach/NPR hide caption

itoggle caption Tom Dreisbach/NPR

A recent Yellow Ribbon Reintegration Program event in Boston offered help for members of the 182nd Infantry Regiment of the Army National Guard as they transition back to being civilians. Tom Dreisbach/NPR hide caption

itoggle caption Tom Dreisbach/NPR

The National Guard's 182nd Infantry Regiment returned home in March from a year in Afghanistan. One in three said they were unemployed or looking for work. Becky Lettenberger/NPR hide caption

itoggle caption Becky Lettenberger/NPR

A portrait of Spc. Jonathan Nestico, 27, is displayed in his family's home in Woburn, Mass. Becky Lettenberger/Becky Lettenberger/NPR hide caption

itoggle caption Becky Lettenberger/Becky Lettenberger/NPR

Members of the 182nd Infantry Regiment arrive in Indiana after spending a year in Afghanistan. They will spend about a week here before returning to their homes in New England. Tom Dreisbach/NPR hide caption

itoggle caption Tom Dreisbach/NPR

A student paints the Facebook logo on a mural commemorating Egypt's revolution last spring. The team from the CIA's Open Source Center monitors social media activity overseas. Manoocher Deghati/AP hide caption

itoggle caption Manoocher Deghati/AP

Pentagon spokesman George Little, speaking Thursday, said U.S. and Pakistani forces both made mistakes that contributed to the Nov. 26 shooting that killed two dozen Pakistani soldiers along the border with Afghanistan. Luis M. Alvarez/AP hide caption

itoggle caption Luis M. Alvarez/AP

Drone pilots fight a war from the safety of bases in the U.S. but confront some of the same wartime stresses as their comrades on the battlefield. Damian Dovarganes/AP hide caption

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