The United States is not a preternaturally inward-looking nation, and isolation is not the natural disposition of Americans. The real question is not whether Americans are prone to isolation or engagement, but how their engagement with the world has evolved, how events have made the United States a superpower, and how these developments have been guided by political leadership. Indeed, the great debates on foreign affairs in American history have not been about whether to have debates on foreign affairs; they have been between the competing visions of American influence in the world.

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