Have the DOD force its suppliers to make their things in the US? Only allow them to import raw materials or low value manufactured elements. Just throwing ideas

Have the DOD force its suppliers to make their things in the US? Only allow them to import raw materials or low value manufactured elements. Just throwing ideas, might not be practical... Are there controls on what suppliers charge? If not, what prevents them from charging as much or more than would be spent on subsidies? If so, what prevents suppliers from just choosing to opt out of the transaction entirely?