That would be Pakistan. Technically there shouldn't be any "sensitivity" if that turned out to be the case (although the Beeb appear to be giving us a bizarre and whopping hint otherwise) - they're a US ally, they're unlike to get any grief for letting the US use their airspace, especially to deal with Afghanistan, there's no reason for them not be dealing with the Muslim UAE... the only real problem there might be that the plane's gone phut over one of the tribal areas where al Qaeda's leadership are allegedly ensconsed, which would be quite amusing.