“There are decades where nothing happens; and there are weeks where decades happen.” I have seen this quote, attributed to Vladimir Ilyich Lenin, trotted out several times in the past few days. In extraordinary times, cliches take on added weight. Given how resonant the quote feels, we are doubtlessly living through extraordinary times. Russia’s war of aggression against Ukraine is not merely a security crisis in Eastern Europe. It is likely to reorder the world in lasting ways. One can feel the change in the air, even if it’s difficult to discern the shape of things to come fully. Something is ending — perhaps, as the historian Hal Brands recently wrote, the so-called liberal world order, or at least the comfortable fictions about the durability of moral and economic progress that had seemed to take root under the umbrella of uncontested American hegemony. Something is being born — the truly multipolar world. It is not a foregone conclusion that America itself, or even more broadly speaking “the West,” will be weaker in this multipolar world. By some measures, the West may even come out stronger. But the limits of its power will be much more clearly marked out. And that will have profound implications for the future. The Ukrainian people stand to lose the most from this war. At the time of writing, more than a million have fled the country. And as the war...