American Exceptionalism is proving, as always, a very hard beast to put down. The belief that this country is not only unique in the world, but has a unique role to play in it is periodically turned out to pasture by some in both parties, and sooner or later finds its way in again. That’s less because of its own perfections than because all other approaches are worse.

The idea began in 1904 when the Dominican Republic defaulted to on its debt to three countries in Europe and Theodore Roosevelt had quickly moved in, seized the customs house in Santo Domingo and settled the debts before the crisis could escalate. This was the first example of the preventive diplomacy he employed in his hemisphere and wished to extend to the world. Accepting the Nobel Peace Prize in 1910 after he brokered peace between Japan and Russia, Roosevelt used his acceptance speech to lobby the world on the need for such measures. “It would be a masterstroke if those great powers honestly bent on peace would form a League of Peace, not only to keep the peace among themselves, but to prevent, by force if necessary, its being broken by others,” he said to his audience.