A thermobaric weapon is a type of explosive that utilizes oxygen from the surrounding air to generate an intense, high-temperature explosion, and in practice the blast wave such a weapon produces is typically significantly longer in duration than a conventional condensed explosive. The fuel-air bomb is one of the most well-known types of thermobaric weapons.

Most conventional explosives consist of a fuel-oxidizer premix (gunpowder, for example, contains 25% fuel and 75% oxidizer), whereas thermobaric weapons are almost 100% fuel, so thermobaric weapons are significantly more energetic than conventional condensed explosives of equal weight. Their reliance on atmospheric oxygen makes them unsuitable for use underwater, at high altitude, and in adverse weather. They do, however, cause considerably more destruction when used inside confined environments such as tunnels, caves, and bunkers - partly due to the sustained blast wave, and partly by consuming the available oxygen inside those confined spaces.

Fuel-air explosive in The Disunited States of AmericaEdit

The fuel-air explosive was an explosive second only to an atomic bomb in its destructive ability.

Ohio used a fuel-air explosive on downtown Parkersburg, Virginia early in the War of 2097. Parkerburg was hurt, but functional, until Ohio forces overran it weeks later.