The Federalist: Another sticking point in the relationship between conservatives and libertarians is foreign policy – not only because there’s a legitimate philosophical disagreement, but because the electorate is mercurial. For a few years, Republicans were more noninterventionist, and then things happen. And when things happen, Americans become more inclined to drop bombs. Is there philosophical guideline conservatarians can follow?

Charles Cooke: There is and I don’t think libertarians will like it. My explanation of Barack Obama’s election and his foreign policy, as it has been stated, is that he not interested in foreign policy and didn’t need to be when he came into power. What I mean by that is that America was engaged at the time of his election in one of its historically normal and customary holidays from intervention. Now, the country was set up on a principle of non-interventionism and a desire to stay out of empire and to stay out of European wars. That was virtuous, I think, and possible for most of American history. But it is not anymore. And so when you see this yo-yoing between where we were in 2008 and where we are now – I think this morning 62 percent of Americans want to send troops to fight ISIS – that is, in my view, the realization of the voting public that since 1945 America has been the indispensable nation. And that we don’t have much of a choice about our role in the world. It’s one thing to be non-interventionist in 1880 and, indeed, it was another one to be on 1918, which was the last real anti-interventionist moment. Well, Vietnam was, but the Cold War overshadowed it.

In 1945, the British, overnight, handed the baton to the United States. And the liberal nation or force that undergirded the national order and was replaced by the U.S., which broadly had the same aim: free trade, security of commerce, the use of the seas for global communication, business, and travel and not for fighting. So I empathize when they go towards that early old republican conception of America’s role in the world. I emphasize with the force that brought Barack Obama’s foreign policy into existence. But I think the world has changed.