After serving mainly as a staff officer in World War I, Guderian remained in the army and became interested in armoured warfare. Attracting Adolf Hitler's (Hitler, Adolf) attention in 1935, he rose rapidly and was able to put many of his revolutionary ideas into practice. His Achtung! Panzer! (1937; Attention! Tanks!) incorporated many of the theories of the British general J.F.C. Fuller and General Charles de Gaulle (Gaulle, Charles de), who advocated the creation of independent armoured formations with strong air and motorized infantry support, intended to increase mobility on the battlefield by quick penetrations of enemy lines and by trapping vast bodies of men and weapons in encircling movements. Unlike most of his reform-minded contemporaries in other armies, Guderian found a sympathetic supporter in his commander in chief, Hitler. Consequently the German army, despite opposition from conservative elements, developed a tactical superiority at the outbreak of World War II that repeatedly ensured victory.

Designated chief of Germany's mobile troops in November 1938, Guderian proved the soundness of his theories in the Polish campaign of September 1939 and spearheaded the drive to the French coast of the English Channel (May 1940) that eliminated France from the war. In the Russian campaign he reached the outskirts of Moscow before being driven back in October 1941. Incurring Hitler's disfavour for withdrawing his troops in the face of a Russian counteroffensive during the winter of 1941–42, he was dismissed, but he returned in March 1943 as inspector general of armoured troops, with authority to establish priorities in the production of armoured vehicles as well as to direct their employment. He simplified and accelerated tank production and, after the July 20, 1944, attempt on Hitler's life, became acting chief of staff. Hitler's interference nullified most of Guderian's actions, however, and he resigned on March 5, 1945. He wrote Erinnerungen eines Soldaten (1951; “Reminiscences of a Soldier”; Eng. trans. Panzer Leader).