An opportunity to kill bad guys can blind presidents and their supporters to the costs and unintended consequences of their actions.
While debating America's drone strikes, the Daily Beast's Andrew Sullivan has been sketching his notion of the responsibilities presidents have to the United States. Opposition to the CIA's drone war "kind of assumes 9/11 didn't happen or couldn't happen again, and dismisses far too glibly the president's actual responsibility as commander-in-chief to counter these acts of mass terror," he writes. "If you accept that presidential responsibility, and you also realize that the blowback from trying to occupy whole Muslim countries will be more intense, then what is a president supposed to do?"
In a subsequent post, he again invokes presidential responsibility, citing the raid that killed bin Laden. By Glenn Greenwald's logic, he argues, "bin Laden should still be sitting in his room, planning new assassinations and terror attacks. Does he think it's even halfway credible for any American president to have contented himself with that? Or is he not living on the same planet I am?"
This is flawed reasoning. It presumes that particular, aggressive military actions are prudent because to do nothing would leave a threat unaddressed. But actions have costs and benefits that must be compared. Do the drone strikes make us better off, despite the terrorists they create? Did the Bin Laden raid make us safer, despite contributing to the destabilization of Pakistan? Andrew Sullivan isn't grappling with these questions. He's presuming that the benefits outweigh the costs without a careful comparison. He's writing as if the president has a responsibility to act regardless of the answer.