I'm also reminded of my experiences in OIF III when we had a company AOR that bisected the city from east to west. One company had the north, the other company had the south. Our AOR boundaries were not published on the internet, but the insurgents were able to quickly figure out where the boundary between us was and figure out that it was a great place to operate because when something went down on the boundary, we had to coordinate between companies to ensure there was no fratricide or other unforunateness. In response to this, we would occasionally shift the boundaries north and south to mix it up a bit. Once the MOI Commandos in our city became a more capable force, we tried to focus their attention on the boundaries between us. It seemed easier to have a third force overlapping our AORs and to keep tabs on them.

I think a similar arrangement could be imagined on the India-Pakistan border. CENTCOM and PACOM suddenly need to coordinate their response. State seems well positioned to help coordinate. Likewise if something goes down on the Iran-Afghanistan border - two State organizations need to coordinate, but CENTCOM is well positioned to help. In light of Otto's comment, obviously this is a simplified analogy.