The years between 1918 and 1939 were marked by intense turmoil for much of the world, as Europe, ravaged by World War I, struggled to rebuild and recover, while the U.S. brought home her late-to-the-war troops and once again downsized its military. In the Pacific, the Japanese military, who had played a limited role in the war on the side of the Entente, took advantage of Germany’s defeat to advance its interests in the region by acquiring the German military colony at Tsingtao, China. All of these events would form the perfect storm that would become the Second World War. The interwar years would find many of the world’s intelligence services lacking and playing catch up.

Germany

For Germany, the years between the world wars were as much a time of refitting and rearmament as they were of recovery. German territory had largely been untouched by the war, but being on the losing side came with consequences. An effective British blockade had brought about famine and hunger, and the largely unpopular war led to the Kaiser and the royal families abdicating, to be replaced by the Weimar Republic. Economically, Germany was suffering from hyperinflation at a time when the rest of the world was reeling from the effects of the Great Depression.

Abwehr, Germany’s military intelligence unit, was formally born in 1920. This was despite the provisions of the Treaty of Versailles, which clearly prohibited the formation of any German intelligence agency. Ignoring this, the German defense ministry established what they labeled as a “defense against foreign espionage.” (Over time, this would morph into something else completely.) The fledgling Abwehr was tasked with domestic and foreign intelligence gathering — the majority of it via HUMINT (human intelligence) — along with counterespionage.

Then in 1929, each individual military branch’s intelligence units were combined and placed under the umbrella of the Ministry of Defense under General Kurt Schleicher. Much like today, the Abwehr operated out of domestic and foreign stations. The foreign stations were first set up in neutral countries and then in occupied nations as the Blitzkrieg rolled on. In 1938, Hitler replaced the Abwehr with the OKW (or Oberkommando der Wehrmacht, “Supreme Command of the Armed Forces”) and made it a part of his personal sphere of influence.