Russia had a huge revolution organized by the Communist Party and they pulled Russia out of the war. The British and French were happy because they could get more land from the Ottoman Empire. The original plan was to give Russia Constantinople (now modern day Istanbul) was to be given to Russia as well as some in land in the Caucasus. Getting Istanbul was huge for Russia as it would allow them access into the Mediterranean. Bottom line is the allies were happy and so was Germany. Hope that was helped and answers your question!