Final answer:
The Bolshevik Revolution and World War I were the two main historical and political events that shaped this phenomenon.
Step-by-step explanation:
The two main historical and political events that shaped this phenomenon were the Bolshevik Revolution and World War I. The Bolshevik Revolution, which took place in 1917 in Russia, resulted in the establishment of the Union of Soviet Socialist Republics (USSR).
This event had a significant impact on political and social ideologies around the world, especially in Europe. World War I, which occurred from 1914 to 1918, led to the downfall of the old order of monarchy and nobility in Europe, and it also had far-reaching consequences on the political landscape of the world.