scorched earth policy
From Longman Dictionary of Contemporary EnglishRelated topics: Militaryscorched earth policyˌscorched ˈearth ˌpolicy noun [countable] PMthe destruction by an army of everything useful in an area, especially crops, so that the land cannot be used by an enemyExamples from the Corpusscorched earth policy• The intention may not have been a scorched earth policy, but the effect on some departments was the same.