V-2 rocket offensive began on 8 September 1944, when "Lehr- und Versuchsbatterie No. 444" () launched a single rocket guided by a radio beam directed at Paris. Wreckage of combat V-2s occasionally contained the transponder for velocity and fuel cutoff. The painting of the operational V-2s was mostly a ragged-edged pattern with several variations, but at the end of the war a plain olive green rocket also appeared. During tests, the rocket was painted in a characteristic black-and-white chessboard pattern, which aided in determining if the rocket was spinning around its longitudinal axis. The original German designation of the rocket was "V2",
Bombing of Tokyo (10 March 1945) for firebombing raids against Japan began well before March 1945. In 1943 the USAAF tested the effectiveness of incendiary bombs on the adjoining German and Japanese-style domestic set-piece building complexes at the Dugway Proving Ground. These trials demonstrated that M69 incendiaries were particularly effective at starting uncontrollable fires. These weapons were dropped from B-29s in clusters, and used napalm as their incendiary filler. After the bomb struck the ground, a fuse ignited a charge which first sprayed napalm from the weapon, and then ignited it. Prior to March 1945, stockpiles of incendiary bombs were built up in the Mariana Islands.