I don't think they've retired all of the Warthogs. The problem is where to base them. They aren't suitable for carrier ops and are so slow, they're the only plane in the Air Force where you have to worry about bird strikes from behind (or so the old joke goes). The Air Force aircraft are having to fly long distances to participate in the attacks. The bombers are mostly from Diego Garcia. The tactical aircraft that I've seen (F-15Es) are apparently flying all the way from Kuwait. That's a very long mission in an A-10. The closer countries like Pakistan are unwilling to let us fly combat missions from their fields.

If we build or capture an airfield relatively close to the battlefield, close air support tactical aircraft like the A-10 probably won't be used. Those planes are designed to be operated close to the troops and, like crop dusters, are designed for quick turn around times from short, rough airfields near the action.