 In the Malayan Campaign, the Burma Campaign and the Pacific Theater, Lend-Lease issue Thompsons were used by the British Army, Indian Army, Australian Army infantry and other Commonwealth forces.They used the Thompson extensively in jungle patrols and ambushes, where it was prized for its firepower, though it was criticized for its hefty weight and poor reliability.Difficulties in supply eventually led to its replacement in Australian Army units in 1943 by other submachine guns such as the Owen and Austen, and British forces also largely replaced it with the Sten gun.