What actions did Russia take that may have hurt the Allied movement?

The Bolshevik government signed in 1918 the Treaty of Brest-Litovsk with the Central Powers that drove out Russia from WWI. The situation was so chaotic in Russia that it allowed the new authorities to focus on domestic issues, even at a terrible cost in terms of lost territory, wealth and population. At the same time, it meant the end of the Eastern Front to the dismay of the Allies on the Western Front. It gave relief to the German army fighting in France and added pressure to the Allied war effort.