In the 1940s, after two world wars and a depression, Western policymakers decided enough was enough. Unless international politics changed in some fundamental way, humanity itself might not survive much longer.
A strain of liberal idealism had been integral to U.S. identity from the American founding onward, but now power could be put behind principle. Woodrow Wilson had fought “to vindicate the principles of peace and justice in the life of the world as against selfish and autocratic power and to set up amongst the really free and self-governed peoples of the world such a concert of purpose and of action as will henceforth ensure the observance of those principles.” Keeping his goals while noting his failures, the next generation tried again with a revised strategy, and this time they succeeded. The result became known as the postwar liberal international order.
The founders of the order embraced cooperation with like-minded powers, rejecting isolationism and casting themselves as player-managers of an ever-expanding team. They bailed out the United Kingdom, liberated France, rehabilitated Germany and Japan, bound themselves to Canada and Mexico, and more. And for seven decades, the allies were fruitful, and multiplied, and waxed exceeding mighty.
Then arose up a new king who knew not Joseph.