The armed service concerned with attack and defence in the air. Aircraft were first used in World War I to locate targets for artillery on the Western Front, but from 1916 onwards they were developed for bombing, while rival fighter aircraft engaged in aerial dogfights both in France and in the Mesopotamian Campaign, where aircraft were also invaluable for reconnaissance. Airships were also constructed, especially by Germany, which used Zeppelin airships for bombing attacks against civilian targets. After disastrous crashes in the 1930s, however, airships lost popularity. Very rapid development in aircraft design between the wars meant that World War II began with both sides possessing formidable bomber and fighter capability. During the war dive‐bombing techniques as well as heavily armed bombers for massed high altitude air raids (bombing offensives) were developed, while the invention of radar assisted defenders in locating attacking aircraft. Large troop‐carrying planes were also introduced, together with the helicopter, which became a key weapon in later wars in Korea, Vietnam, and Afghanistan. The Cold War, from the late 1940s to 1990, saw the deployment by the superpowers of strategic nuclear bombers and intercontinental ballistic missiles (ICBMs). With the advent of supersonic flight, the high costs of increasingly sophisticated aircraft since World War II have led to the design of aircraft that each fulfil several roles, often jointly developed by a consortium of nations. Air power was decisive in the Gulf War of 1991. This saw the first large‐scale use of several innovations, such as laser‐guided bombs and computer‐guided cruise missiles, that were able to pinpoint and destroy specific targets. A further development was the use of the Stealth bomber, which was designed to evade and destroy radar defences. Since the late 2000s the USA has used unmanned aircraft, known as ‘drones’, in Afgahnistan and elsewhere. Some drones are controlled by computers; others still have human pilots, but these are located remotely, often thousands of miles away in the USA.