A number of suggestions of brute-force approaches to demining have been made. If mined terrain is unusable, one may be willing to accept substantial damage in order to restore it for habitation or agriculture. The ideal would be a way to detonate all the mines in an area by a cheap energy release with no lingering after-effects. Fuel-air explosives detonated above the mine field have been proposed, and the U.S. Army is looking into sprayable foam explosives formed of components which are separately inert. Detonation of buried munitions by microwave heating of the ground has also been proposed, but the electrical power requirements are difficult to meet in remote field conditions. None of these techniques have been proved in actual minefields.