The GAO says we don't have enough air planes. David Axe says that this is "embarrassing" and that it means the end of us as a "superpower".
I'm not so sure. The whole point is that (by 2020) we would not have enough fighters left to perform "air sovereignty missions", which are supposed to protect us from foreign bombers and incoming airborne terrorists. I really have to say that the first is not that big a deal anymore, and the second has already failed because the terrorists are smart enough not to enter US airspace like that.
The other thing that's involved is fighting smuggling--do we really need a bunch of Raptors or F=35s for that?