Answer:
By ending Russia's involvement in the conflict.
Step-by-step explanation:
The Brest-Litovsk Treaty, signed on March 3, 1918, in the homonymous city of Belarus (then part of the Russian Empire), sealed the “peace” between Russia (already taken by the Bolshevik revolutionaries) and the central empires against the which had entered the war, especially Germany and Austria-Hungary. Russia's departure from World War I altered course, as England lost a strong ally.
Leaving Russia seemed an advantage to Germany, but the winds of war changed after this treaty was signed. Germany and its allies were ostensibly crushed by England, France, the United States, and the other countries associated with them.