It's not paranoia if they really are out to get you. Now of course we've seen a lot of geopolitical struggles between major world powers here on Crash Course, but this time there was this special added bonus that war could lead to the destruction of the human species. That was new for world history and it's worth remembering it's still new. Here's the period of time we've discussed on Crash Course and this is how long we've had the technological capability to exterminate ourselves. So that's worrisome. Immediately after World War II, the Soviets created a sphere of influence in Eastern Europe, dominating the countries where the Red Army had pushed back the Nazis. Which is why Winston Churchill famously said in 1946 that an iron curtain had descended across Europe.