His father used his connections with the royal family to get Himmler accepted as an officer candidate, and he enlisted with the reserve battalion of the 11th Bavarian Regiment in December 1917.
Fighting in Moldova continued in 1917, but Russian withdrawal from the war in late 1917 as a result of the October Revolution meant that Romania was forced to sign an armistice with the Central Powers on 9 December 1917.
In December, the Central Powers signed an armistice with Russia, thus freeing large numbers of German troops for use in the west. With German reinforcements and new American troops pouring in, the outcome was to be decided on the Western Front.