Asked, early in his presidency, whether he believed in American exceptionalism, Barack Obama gave a telling reply. "I believe in American exceptionalism, just as I suspect the Brits believe in British exceptionalism and the Greeks believe in Greek exceptionalism."

The first part of that answer is fascinating (we'll come back to the Greeks in a bit). Most Brits do indeed believe in British exceptionalism. But here's the thing: They define it in almost exactly the same way that Americans do. British exceptionalism, like its American cousin, has traditionally been held to reside in a series of values and institutions: personal liberty, free contract, jury trials, uncensored newspapers, regular elections, habeas corpus, open competition, secure property, religious pluralism.

The conceit of our era is to assume that these ideals are somehow the natural condition of an advanced society—that all nations will get around to them once they become rich enough and educated enough. In fact, these ideals were developed overwhelmingly in the language in which you are reading these words. You don't have to go back very far to find a time when freedom under the law was more or less confined to the Anglosphere: the community of English-speaking democracies.

In August 1941, when Franklin Delano Roosevelt and Winston Churchill met on the deck of HMS Prince of Wales off Newfoundland, no one believed that there was anything inevitable about the triumph of what the Nazis and Communists both called "decadent Anglo-Saxon capitalism." They called it "decadent" for a reason. Across the Eurasian landmass, freedom and democracy had retreated before authoritarianism, then thought to be the coming force. Though a small number of European countries had had their parliamentary systems overthrown by invaders, many more had turned to autocracy on their own, without needing to be occupied: Austria, Bulgaria, Estonia, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Poland, Portugal, Romania, Spain.

Churchill, of all people, knew that the affinity between the United States and the rest of the English-speaking world rested on more than a congruence of parliamentary systems, and he was determined to display that cultural affinity to maximum advantage when he met FDR.