A Russian invasion of Ukraine would look like the kind of war that has been largely absent in the past 80 years and that was once common. It would involve a powerful nation setting out to expand its regional dominance by taking over a neighbor. A war like this - a voluntary war of aggression - would be a sign that Putin believed that Pax Americana was over and that the U.S., the European Union and their allies had become too weak to exact painful consequences.
