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.
Wars of Alexander the Great
In these early months, Darius still refused to take Alexander seriously or mount a serious challenge to Alexander's movements. Memnon of Rhodes, the Greek mercenary who aligned himself with the Persians, advocated a scorched earth strategy. He wanted the Persians to destroy the land in front of Alexander, which he hoped would force Alexander's army to starve, and then to turn back. The satraps in Anatolia rejected this advice, considering it their duty to defend their land. Eventually, with Alexander advancing deeper into Persian territory, Darius ordered all five satraps of the Anatolian provinces to pool their military resources together and confront Alexander. This army was guided by Memnon, while absolute command was split among the five satraps.