Soviet Union: This was a federal socialist state in northern Eurasia that existed from 1922 to 1991. It's like an old version of the puzzle where some pieces were differently shaped or colored.
Russian Revolution: A period of political and social revolution across the territory of the Russian Empire which led to the establishment of the Soviet Union. This event can be seen as someone shaking up the puzzle box and rearranging all the pieces.
Cold War: A period of geopolitical tension between powers in Eastern Bloc (Soviet Union and its satellite states) and powers in Western Bloc (United States, NATO allies). The Cold War can be likened to two people arguing over how to put together this complex puzzle.