Article Photos: WHY IT MATTERS: Issues at stake in election 36/40

  FILE- In this Nov. 5, 2009, file photo, an entrance to Fort Hood Army Base in Fort Hood, Texas, near Killeen remains in lock-down following a mass shooting. Osama bin Laden is dead and there hasn’t been a successful attack by al-Qaida-inspired extremists on U.S. soil since the deadly shooting rampage in Fort Hood, Texas, in 2009. But the danger of terrorism remains a reality for Americans, as seen in the attack in Libya in September that killed U.S. Ambassador Chris Stevens and three other Americans. (AP Photo/Jack Plunkett)