A firestorm is a conflagration which attains such intensity that it creates and sustains its own wind system. It is most commonly a natural phenomenon, created during some of the largest bushfires, forest fires, and wildfires. The Great Peshtigo Fire is one example of a firestorm. Firestorms can also be deliberate effects of targeted explosives such as occurred as a result of the aerial bombings of Dresden and Tokyo during World War II.

Strategic bombing during World War II was greater in scale than any wartime attack the world had previously witnessed. The strategic bombing campaigns conducted by Nazi Germany, the United Kingdom, the United States and the Empire of Japan used conventional weapons, incendiaries, and nuclear weapons.

Mid-way through the war, the United States Army Air Forces arrived to begin its own strategic bombing campaign, which was conducted in daylight. In Europe, the American Eighth Air Force heavy bombers carried smaller payloads than British aircraft because of the need for defensive armament. USAAF leaders firmly held to the claim of "precision" bombing of military targets for much of the war, and energetically refuted claims that they were simply bombing cities. In reality, the day bombing was "precision bombing" only in the sense that most bombs fell somewhere near a specific designated target such as a railway yard, whereas the night bombing campaign targeted cities with area bombardment. Nevertheless, the sheer tonnage of explosive delivered by day and by night was eventually sufficient to cause widespread damage, and, more importantly from a military point of view, forced Germany to divert resources to counter it. This was to be the real significance of the Allied strategic bombing campaign—resource allocation.