Obama has also relied extensively on other governments to supply ground forces to fight terrorist groups abroad; this represents a second major pillar in his strategy. The policy has obvious appeal: if the United States cares more about the threat than local authorities do, U.S. interventions are unlikely to succeed in the long run. But this policy, too, is fraught with risk and can lead to significant blowback. Critics argue that it is hard to identify potential enemies among the forces Washington trains: consider the many “green on blue” attacks that have taken place in Afghanistan in the past dozen years, in which Afghan soldiers or police officers have killed members of the coalition forces tasked with training them. In Syria, where the Obama administration is not partnering with the government in Damascus but instead hopes to train rebel forces to fight ISIS, U.S. officials have identified only 60 volunteers who have the “right mindset and ideology,” according to U.S. Secretary of Defense Ashton Carter. Similar efforts in Iraq have also been slowed by a lack of acceptable recruits. Whatever the virtues of this policy, it will not work if Washington cannot identify suitable candidates.