Tyler Cowen makes a number of questionable claims in this article, but this is by far the strangest:

To make matters more difficult, the American public is often pretty squeamish about violence and conflict abroad. That’s overall a good thing, but it means a “get tough” foreign policy isn’t very easy to implement in a credible fashion [bold mine-DL]. (For instance the American public approved when President Obama neglected his “line in the sane” [sic] commitment regarding Syria and chemical weapons use.) For better or worse, the electorate stands in the way of what might otherwise be a strategically optimal foreign policy.

Cowen doesn’t ever spell out what he means by “strategically optimal foreign policy,” so it’s hard to know what bother him about American “squeamishness” in the Syrian case. Does he think that the U.S. should have bombed Syria last year? That is what this paragraph implies, but it’s not clear how this serves his stated goal of “having a good foreign policy.” In what way would it have been “optimal” for the U.S. to get into a new war with the Syrian government last year? Cowen is frustratingly vague about what he thinks a “good” foreign policy would look like beyond endorsing existing alliances. It’s not entirely clear whether he buys into discredited claims about the importance of maintaining “credibility,” and he doesn’t quite say whether he accepts the hawkish argument that American “credibility” was squandered in Syria to our detriment.

As for the idea that Americans are “squeamish” about violence overseas, I don’t know what he’s talking about. Americans recoiled from intervention in Syria last year because they didn’t see how military action would achieve anything, and they wanted the U.S. to steer clear of Syria’s civil war. It wasn’t because they were “squeamish” about the use of force, but because they didn’t approve of what they perceived to be a futile mission. No one can seriously look back at the modern history of American public opinion on war and conclude that Americans are put off by the idea of violence and conflict. That was what made the Syrian debate last year so extraordinary. Unlike virtually every other proposed intervention before or since, a large majority rejected military action. Unfortunately, as the popular response to the war against ISIS has made clear, that appears to have been the exception. Most Americans are usually only too ready to support military action when the president claims it to be necessary, so it is strange to think that the electorate is “getting in the way.” It was very welcome when a large majority did get in the way of a misguided plan to bomb Syria, but as we know very well that is not at all common.