There are plenty of problems with U.S. President Barack Obama's targeted killings in the war against terrorism: The policy remains secret in most aspects, involves no judicial review, has resulted in the deaths of innocent civilians, has been employed far from any battlefield and has sparked deep anti-American resentment in countries where we can ill afford it.

But when it comes to the particular legal issue raised in a recently leaked "white paper" from the Justice Department — namely, whether it is legal to kill Americans with drones — one problem looms largest: The policy permits the government to kill its citizens in secret while refusing to acknowledge, even after the fact, that it has done so.

There may be extraordinary occasions when killing a citizen is permissible, but it should never be acceptable for the government to refuse to acknowledge the act. How can we be free if our government has the power to kill us in secret? And how can a sovereign authority be accountable to the people if the sovereign can refuse to own up to its actions?