** FILE ** Ringo, a bomb-sniffing dog, listens to trainer Adam Ward, a contractor working for American K-9 Interdiction, as dog handler Marine Cpl. William Childs observes in Helmand province, Afghanistan, in 2009. The Pentagon also has spent more than $200 million a year developing devices to detect roadside bombs. (Associated Press)

** FILE ** Ringo, a bomb-sniffing dog, listens to trainer Adam Ward, a contractor working for American K-9 Interdiction, as dog handler Marine Cpl. William Childs observes in Helmand province, Afghanistan, in 2009. The Pentagon also has spent more than $200 million a year developing devices to detect roadside bombs. (Associated Press)