Eric Posner writes: The Wall Street Journal recently reported on debates within the Obama administration about the legality of the drone war in Pakistan. State Department legal adviser Harold Koh, the former dean of Yale Law School and even more former darling of the left for his criticisms of the Bush administration’s aggressive theories of executive power, plays a prominent role in them. Koh apparently concluded that the drone war “veers near the edge” of illegality but does not quite tumble over it.

That is a questionable judgment. The U.N. Charter permits countries to use military force abroad only with the approval of the U.N. Security Council, in self-defense, or with the permission of the country in which military force is to be used. The U.N. Security Council never authorized the drone war in Pakistan. Self-defense, traditionally defined to mean the use of force against an “imminent” armed attack by a nation-state, does not apply either, because no one thinks that Pakistan plans to invade the United States. That leaves consent as the only possible legal theory.

But Pakistan has never consented to the drone war. Publicly and officially the country has opposed it. Before the raid that killed Osama bin Laden in May 2011, the CIA sent a fax every month to Pakistan’s Inter-Services Intelligence agency that would identify the airspace in which drones would be sent. The ISI would send back an acknowledgment that it had received the fax, and the U.S. government inferred consent on the basis of the acknowledgments. But after the raid, the ISI stopped sending back the acknowledgments.

Now what to do? The administration argues that consent can still be inferred despite the unanswered faxes. The reason is that “the Pakistani military continues to clear airspace for drones and doesn’t interfere physically with the unpiloted aircraft in flight” — meaning that Pakistan does not shoot down the drones or permit private aircraft to collide with them.

We might call this “coerced consent.” Consider it this way: You walk into a jewelry store and the proprietor announces that he will deem you to have consented to the purchase of a diamond tiara for $10,000, despite all your protests to the contrary, unless you use physical force to stop him as he removes your wallet from your pocket. Imagine further that he’s 7 feet tall and weighs 400 pounds. This is what a Pakistani official meant when he told the Wall Street Journal that shooting down a drone would be “needlessly provocative.” He meant that such an action would risk provoking retaliation from the United States, a risk that Pakistan cannot afford to take. Because Pakistan lies prostrate and endures the pummeling rather than makes a futile effort to stop it, it is deemed to consent to the bombing of its own territory. [Continue reading…]