(Not a military)

Cutting the supply lines is one of the most classic military strategy. In most armies there is way more soldiers involved in logistic and support than soldier actually fighting. If you want to get rid of the soldier fighting on the front-line you can send other soldier fighting against them, but they are trained and ready to fight or you can just cut the supply lines by destroying bridge and bombing supply truck/trains. During Napoleon's Russian campaign (people will start to believe I am obsessed with Napoleon) russia did burn the crop before withdrawing, and it's how once they reached Moscow the soldier had no food left and Napoleon's great army died from starvation while retreating under Russian winter