Defense Secretary Ash Carter testifies on Capitol Hill in Washington, earlier this month. In an interview on CNN today, Carter complained that Iraqi forces lacked "the will to fight" the self-declared Islamic State. Manuel Balce Ceneta/AP hide caption

itoggle caption Manuel Balce Ceneta/AP

Princeton University professor John Nash speaks during a news conference at the university in Oct. 1994 after being named the winner of the Nobel Prize for economics. Charles Rex Arbogast/AP hide caption

itoggle caption Charles Rex Arbogast/AP

A carry team at Dover Air Force Base trains on the proper protocol for a dignified transfer. Ariel Zambelich/NPR hide caption

itoggle caption Ariel Zambelich/NPR

A protestor films riot police Saturday as they advance on a small march against the acquittal of Michael Brelo, a Cleveland patrolman charged in the shooting deaths of two unarmed suspects. John Minchillo/AP hide caption

itoggle caption John Minchillo/AP

Students walk through a gate on the Harvard University campus. In a recent complaint, dozens of groups have alleged that the school's admissions process holds Asian-American applicants to an unfairly high standard. Elise Amendola/AP hide caption

itoggle caption Elise Amendola/AP

Michael Brelo weeps as he hears the verdict in his trial Saturday, in Cleveland. Brelo, a patrolman charged in the shooting deaths of two unarmed suspects during a 137-shot barrage of gunfire was acquitted. Tony Dejak/AP hide caption

itoggle caption Tony Dejak/AP

Former Defense Secretary Robert Gates at the Boy Scouts of America's annual meeting in 2014. "There's no certainty about any of this," he says of the situation in Iraq. Mark Zaleski/AP hide caption

itoggle caption Mark Zaleski/AP

Authorities investigate a shooting in the parking lot of the Twin Peaks restaurant Sunday in Waco, Texas. Bikers say that most of the 170 people arrested had nothing to do with the violence. Jerry Larson/AP hide caption

itoggle caption Jerry Larson/AP

Francisco Ramirez, a sexual-health educator, offers free advice to a passerby. Christopher Gregory for NPR hide caption

itoggle caption Christopher Gregory for NPR