Air Force I would agree with, if it wasn't for Tom Clancy's HAWX. It does use technology that doesn't exist (Mind you, it takes place in between the years of 2016-2020s), but it uses real planes with realistic states, and you can use Russian planes as well as American (Because we know if the Air Force had its own game, we'd only be able to use American planes). Granted, it lacks strategic bombers and other planes, and it could use more variety than "DESTROY THE TANKS, PROTECT THE FLEET, DESTROY ENEMY BANDITS, ESCORT THE PLANE, DESTROY THE TANKS, etc, etc".
Coast Guard, however, sounds stupid. I mean, unless we do something completely unrealistic like a Ruskie or Chinese invasion, the missions will be like "PREVENT THE ILLEGAL CUBAN IMMIGRANTS FROM GETTING TO THE SHORE, STOP THE DRUG TRAFFICER, PREVENT THE ILLEGAL CUBAN IMMIGRANTS FROM GETTING TO THE SHORE, etc, etc.".