To the following was an effect of allied defeats and high casualty rates on the eastern front

In World War I, the Eastern Front basically comprised of the outskirts between Austria-Hungary, Germany, and Bulgaria on the west, and Russia and Romania on the east. In World War II, the Eastern Front stretched out from Germany's outskirt with Poland in the north to Ukraine's verge on the Black Sea. Russia encountered an unrest and dropped out of the war was an impact of Allied annihilations and high setback rates on the Eastern Front.