Answer:
Now of course we've seen a lot of geopolitical struggles between major world powers here on Crash Course, but this time there was the 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.
Step-by-step explanation: