In late 1918, American engineers designed a prototype rocket-powered, recoilless weapon; but with war ending, further development was postponed. In late 1942, the Rocket Launcher, M1A1 was introduced as an anti-tank weapon. The hand-held weapon fired high explosive anti-tank warheads against armored vehicles, machine gun nests and fortified bunkers at ranges exceeding that of hand-thrown grenades. The weapon, widely employed by the U.S. Army, soon became known as a bazooka, presumably because of its vague resemblance to a musical instrument.
When captured American bazookas fell into their hands early in late 1942, German scientists reverse-engineered a model with a larger warhead that was called Panzerschreck (Tank terror).
A bazooka fire team was often exposed while aiming and a large back blast and smoke trail further identified their position. As a result, casualties among team members were extremely high.
Despite the introduction of the more powerful M9 bazooka in late 1943, the weapon became less effective in the European campaign toward the end of WWII as thicker cast iron-plated tanks were introduced by Germany.
In the Pacific War, the bazooka was effective against small Japanese concrete bunkers and pill boxes, but less so against coconut and sand emplacements. Additionally, the battery-operated firing circuit was easily damaged during rough handling, and rocket motors often failed with high temperatures and exposure to, moisture, salt air, or humidity.