GOP presidential hopefuls use 140 characters or less to answer the question: "As president, how will you avoid continually raising the debt ceiling?" Amy Ta/NPR hide caption

itoggle caption Amy Ta/NPR

Darryl St. George, a Navy corpsman with Weapons Company of the 2nd Battalion, 8th Marines out of Camp Lejeune, N.C., reads a book as the sun rises over a temporary base nicknamed "Patrol Base Suc" in Helmand province, southern Afghanistan. David Gilkey/NPR hide caption

itoggle caption David Gilkey/NPR

A Marine walks along a mud wall while conducting a search and clearing operation in Afghanistan's Helmand province, as the dust from a wheat thrashing machine falls like snow. David Gilkey/NPR hide caption

itoggle caption David Gilkey/NPR

Marine Lance Cpl. Andrew Zemore, 23, from Fredericksburg, Va., is a self-described troublemaker who liked to party too much. Zemore said he fell into the Marine Corps and now is on a Explosives Ordinance Disposal team, searching out bombs with a hand-held metal detector. David Gilkey/NPR hide caption

itoggle caption David Gilkey/NPR

Marines detonate a homemade explosive device in the Helmand River valley in Afghanistan in 2009. David Gilkey/NPR hide caption

itoggle caption David Gilkey/NPR

Air conditioners keep tents cool on a U.S. military base in Iraq. The tents have been treated with polyurethane foam to increase energy efficiency. Courtesy Steven Anderson hide caption

itoggle caption Courtesy Steven Anderson

Army Spc. Christopher B. Fishbeck of Buena Park, Calif., poses for a photo on a rooftop during his tour of duty in Iraq. Courtsey of Fishbeck's Family hide caption

itoggle caption Courtsey of Fishbeck's Family

Alex Horton sits against a wall in Baqubah, Iraq, shortly after a firefight. Courtesy of Alex Horton hide caption

itoggle caption Courtesy of Alex Horton