Historian James Corum criticised the German leadership for failing to understand the technical advances of the First World War, having conducted no studies of the machine gun prior to the war, and giving tank production the lowest priority during the war. Following Germany's defeat, the Treaty of Versailles limited the Reichswehr to a maximum of 100,000 men, making impossible the deployment of mass armies. The German General Staff was abolished by the treaty but continued covertly as the "Truppenamt" (Troop Office), disguised as an administrative body. Committees of veteran staff officers were formed within the "Truppenamt" to evaluate 57 issues of the war to revise German operational theories. By the time of the Second World War, their reports had led to doctrinal and training publications, including H. Dv. 487, "Führung und Gefecht der verbundenen Waffen" (Command and Battle of the Combined Arms), known as das Fug (1921–23) and "Truppenführung" (1933–34), containing standard procedures for combined-arms warfare. The "Reichswehr" was influenced by its analysis of pre-war German military thought, in particular infiltration tactics, which at the end of the war had seen some breakthroughs on the Western Front and the manoeuvre warfare which dominated the Eastern Front.