Answer:
A scorched-earth policy is a military strategy that aims to destroy anything that might be useful to the enemy. Any assets that could be used by the enemy may be targeted, which usually includes obvious weapons, transport vehicles, communication sites, and industrial resources. However, anything useful to the advancing enemy may be targeted, including food stores and agricultural areas, water sources, and even the local people themselves, though the last has been banned under the 1977 Geneva Conventions.
Kuwaiti oil fires set by retreating Iraqi forces in 1991
The practice can be carried out by the military in enemy territory or in its own home territory while it is being invaded. It may overlap with, but is not the same as, punitive destruction of the enemy's resources, which is usually done as part of political strategy, rather than operational strategy.
Notable historic examples of scorched-earth tactics include William Tecumseh Sherman's March to the Sea in the American Civil War, Kit Carson's subjugation of the American Navajo Indians, Lord Kitchener's advance against the Boers, and the setting of fire of 605 to 732 oil wells by retreating Iraqi military forces in the Gulf War. Also notable were the Russian army's strategies during the failed Swedish invasion of Russia, the failed Napoleonic invasion of Russia, the initial Soviet retreat commanded by Joseph Stalin during the German Army's invasion during the Second World War, and Nazi Germany's retreat on the Eastern Front.
The concept of scorched earth is sometimes applied figuratively to the business world in which a firm facing a takeover attempts to make itself less valuable by selling off its assets.