Looking at the map, why would Russia's withdrawal impact the war in favor of Germany?

I don't know if there is answer choices, but it would be:

Germany would no longer have to fight two fronts, this being the Eastern Front.

Explanation:

During WW1 Germany was fighting both the Western and Eastern Fronts, and had launched an invasion of Russia, but failed. Russia would later withdraw in 1917 when the Russian Civil War began.

you didn't give any answers to choose from so i can't with this but, i do know something that the mexican government would be worried about and that is the wall that donald trump is currently trying to get up.