The A-10 is a flying anti-tank barrage platform. A 1-2 second burst from its integral Gatling gun will shred anything that is only of moderate quality armor, and even rip up heavy armor pretty seriously.
Coming in at some 350 knots about a hundred feet off the deck, a couple bursts would break up the most disciplined convoy. And there is practically no defense that could respond fast enough from the ground. Add to this the capability to launch air to surface missiles from practically over the hill up to six miles away, and even the sound of approach must be a little hard on morale for the enemy troops.
... because there is virtually no sound of approach. Twice a year, on Memorial Day and July 4, the A-10s of the Maryland National Guard fly over my house. You don't hear a thing until they're already there. It's amazing. Maybe it's an artifact of the local geography or something, but I swear you don't hear them until they're over your house.