What requirements are needed to fly an approach that requires you to fly over the US/Mexico border?
I had flown my plane (small 4-seater) from Houston to California a few years ago and on the way back, I stopped in El Paso to refuel and sleep for the night.  While in contact with the tower, following whatever vectors they were giving me, I noticed that I was about to cross into Mexico.  It's pretty obvious from the style of buildings and how close they are together that one area is Mexico and the other area is the US, especially at 1000 ft (or less) AGL.  I asked the controller if this was correct since it would put me across the border into Mexico.  I seem to remember him saying something about they had an agreement with Mexico that allowed them to use / control that airspace.