Russia’s invasion of Ukraine has shocked the world, but in many ways Vladimir Putin has been building up to this for some time.

On February 15 Professor John J. Mearsheimer gave a talk (video) about the Ukraine crisis. He starts out (at 3min) by explaining who has caused it: “The United States, mainly, and its allies are responsible for this crisis.”

It’s not easy to make sense of how the United States and Europe are responding to Russia’s aggression.