Hammerstein worked out first tactical concepts for the army in the Truppenamt. They provided for a sustained defense in an attack until the League of Nations would intervene. However, in 1930, he created the first mobilization plan since 1923, which sought to triple the number of infantry divisions from seven to 21. In 1930 he was appointed Commander-in-Chief of the Reichswehr, replacing General Wilhelm Heye. Schleicher (now defense minister) made Hammerstein his successor with support from Brüning. On 1 November 1930, he entered the field with the simultaneous promotion to General of Infantry. There, he created a rearmament program, demanding the formation of at least 42 divisions.