Scorched-earth defense
The scorched-earth defense is a form of risk arbitrage and anti-takeover strategy.
Early thermal weapons
Devastation by fire was not only used as an offensive tactic; some countries and armies employed 'scorched earth' policies on their own land to deprive invading armies of all food and forage. Robert I of Scotland reacted to the English invasion of 1322 by launching punitive and diversionary chevauchées into north-west England, then retreating to Culross, burning as he went the Scottish lands which lay in the path of the English army. The English ran out of food and had to abandon the campaign. Kitchener employed scorched earth tactics to subdue Boer forces in South Africa when three years of warfare had resulted in a stalemate.