Both New Zealand (in 2001) and the Philippines (in 2005) have abandoned trying to maintain fighter jets in their air forces. They have retained helicopters, reconnaisance aircraft and a few close air support or anti-civilian craft interceptors. But, they have come to the strategic conclusion that they would lose anyway against any plausible military opponent that their fighter jets might encounter (China, for example). These nations will now rely on allies, like the United States, in the event of an invasion.
This doesn't make sense for the United States as a whole. But, it does make sense for Air National Guard units in the United States, a concept that I've previously discussed on this blog here.