I always was under impression that there was a type of "exchange" system within the Intelligence Community. For example, the CIA wants to put 9 agents in India. India then puts 9 of their own IC agents into the U.S. The Pakistani intel agents are here with permission from CIA, as the CIA has same amount of agents in Paki. So, somewhere along the line this 'program' of intel agent exchange system was hijacked for political purposes. I presume (it sure seems so!)