Scorched earth
A scorched-earth policy is a military strategy that aims to destroy anything that might be useful to the enemy while it is advancing through or withdrawing from a location. Any assets that could be used by the enemy may be targeted, for example food sources, water supplies, transportation, communications, industrial resources, and even the locale's people themselves.
History of guerrilla warfare
To counter these tactics, the British under Kitchener interned Boer civilians into concentration camps and built hundreds of blockhouses all over the Transvaal and Orange Free State. Kitchener also enacted a scorched earth policy, destroying Boer homes and farms. Eventually, the Boer guerrillas surrendered in 1902, but the British granted them generous terms in order to bring the war to an end. This showed how effective guerrilla tactics could be in extracting concessions from a militarily more powerful enemy.