Even before Britain entered World War Two in 1939, the Soviet Union defeated the Japanese Sixth Army
When it came to mechanical devices, J Walter Christie was blessed with a notably fecund imagination. In 1916, he designed for the US Army Ordnance Board a self-propelled gun carriage. Unfortunately, Christie was not blessed with an agreeable disposition, and when the board asked him to modify it to suit those who would take it to war, he refused. In the early 1920s, Christie designed and built an amphibious light tank. This was demonstrated during the 1924 winter manoeuvres. Rough surf meant that the tank failed to land during the period in which the manoeuvres were held, but it successfully landed afterwards.
The US Marines thought that it had potential, but again nothing came of it. Nor did anything come of subsequent tank designs Christie submitted to the Ordnance Board.