Reverse engineering is often used by militaries in order to copy other nations’ technologies, devices or information that have been obtained by regular troops in the fields or by intelligence operations. It was often used during the Second World War and the Cold War. Well-known examples from WWII and later include

Jerry can: British and American forces noticed that the Germans had gasoline cans with an excellent design. They reverse-engineered copies of those cans. The cans were popularly known as “Jerry cans”.

Tupolev Tu-4: Three American B-29 bombers on missions over Japan were forced to land in the USSR. The Soviets, who did not have a similar strategic bomber, decided to copy the B-29. Within a few years, they had developed the Tu-4, a near-perfect copy.

V2 Rocket: Technical documents for the V2 and related technologies were captured by theWestern Allies at the end of the war. Soviet and captured German engineers had to reproduce technical documents and plans, working from captured hardware, in order to make their clone of the rocket, the R-1, which began the postwar Soviet rocket program that led to the R-7 and the beginning of the space race.

K-13/R-3S missile (NATO reporting name AA-2 ‘Atoll), a Soviet reverse-engineered copy of the AIM-9 Sidewinder, made possible after a Taiwanese AIM-9B hit a Chinese MiG-17 without exploding; amazingly, the missile became lodged within the airframe, the pilot returning to base with what Russian scientists would describe as a university course in missile development.

BGM-71 TOW Missile: In May 1975, negotiations between Iran and Hughes Missile Systems on co-production of the TOW and Maverick missiles stalled over disagreements in the pricing structure, the subsequent 1979 revolution ending all plans for such co-production. Iran was later successful in reverse-engineering the missile and are currently producing their own copy: the Toophan.

China has reversed many examples of Western and Russian hardware, from fighter aircraft to missiles and HMMWV cars.