Pakistan’s behavior in general has been at best ambiguous. Despite having the capacity to “‘trace and detect any aircraft’” operating near its border with Pakistan and (apparently) the ability to shoot such aircraft down, there have never been reports of Pakistan shooting down a U.S. drone. Although the absence of public reports of such downings is not dispositive, the fact that U.S. drones carry out any strikes even though they are slow moving, are not maneuverable, and carry no air defense countermeasures, strongly suggests that Pakistan is choosing not to interdict drones. Additionally, Pakistan has a modern air force that is at least as capable as the Iranian air force but, while Iran has chased a number of U.S. air force drones over the Persian Gulf in recent months, there have never been any similar reports from Pakistan. Finally, and perhaps most tellingly, Pakistan has not taken the sort of concrete steps vis-à-vis the United States for drone strikes as it has for other violations of Pakistani sovereignty. For example, in November 2011, a frontier incident between U.S. and Pakistani troops (that resulted in the death of 26 Pakistanis), led Pakistan to both close its border with Afghanistan to NATO convoys and to kick U.S. drones out from their Pakistani bases. Pakistan also upgraded its Afghan-border air defense systems. Similarly, after a CIA contractor killed two Pakistanis in January 2011, Pakistan ousted all CIA contractors and reduced the number of U.S. special operators allowed in Pakistan for training missions from 120 to 39. Not only has Pakistan not taken such steps in response to U.S. drone strikes, at least until the Wall Street Journal report at the end of September 2012, Pakistan continued to clear the parts of its air space in which the CIA indicated it would conduct drone strikes. That is to say, not only is Pakistan not intervening to prevent drone strikes, it is taking affirmative steps to facilitate those strikes. Thus, Pakistan’s behavior at least renders its public statement ambiguous and, more likely, supersedes those statements altogether. Again, consent must be clearly stated but clearly stated to the recipient of that consent not the outside world.
If the United States is operating without Pakistan’s consent within Pakistan, it is violating Pakistan’s sovereignty—and it may be violating international law. However, Emmerson’s conclusion notwithstanding, it is far from clear that, as a matter of international law, the United States is violating Pakistani sovereignty.