2. What turning point occurred in
Russia in 1917?

The beginning of the Russian revolution, and Russia leaving WW1 as a result. Rebels, commonly referred to as the Red Army, wanted a communist government. They fought around Russia against the White Army (the Bolshevik government in place at the time.) Russia leaving the war allowed Austria-Hungary and Germany to focus more soldiers on the western front against Italy, Britain, France, and the US.

To have a bunch of countries to team up, and communicate not let the communist break them apart and take over the world