’The Great Doctrine Disaster’: Reform, Reaction, and Mechanization in the British Army, 1919–1939

Historians have argued that Britain lost its early lead in developing mechanized formations in the interwar period due to financial pressures, inter-arm rivalry, poor tank design, and the misjudgments of tank enthusiasts. A systematic examination of armor doctrine, however, demonstrates that British approaches were coherent and innovative until 1935. Progress was derailed by the suppression of the “Tank Training” (1935) manual and the decision to mechanize the cavalry rather than expand the Royal Tank Corps. Coordination between manuals of arms of service and the field service regulations was abandoned, moreover, in favor of multiple training pamphlets. The result was the “Great Doctrine Disaster” caused by fallacious assumptions about tank design, tactics, and the future battlefield.