Eventually you will want to tear down some of the defenses you’ve built, perhaps to rebuild them elsewhere, replace them with a new configuration of defenses, or relocate your nation’s territory to a different part of the map. This is called salvaging the defense. When your nation salvages a defense, it will recoup some of the manpower spent building that defense (the portion recouped is determined by the nation’s Salvage Value stat), and will also stop spending the hourly energy cost required to maintain that defense.
To salvage a defense, click (or tap) on the defense and select Salvage from the menu. To both salvage the defense and evacuate the land square that it’s located on, click (or tap) and select Salvage and Evacuate from the menu. If you’re using a device with a keyboard, you can click on a square while holding down the Shift key to salvage a defense in that square.