Probably the most important foreign policy challenge that a country can face is deciding when to go to war. And, based on a new study, the American public is much more hawkish on this issue than are the country's international relations experts.

There's been some sense of this gap for a while, but a new study — from the researchers at William & Mary and the University of Wisconsin — confirmed it. The researchers asked an identical set of questions about war to a random sample of Americans and academics who study international relations. An analysis of the data by two scholars found that in almost all situations, the public is more likely to support wars than the experts are.

The reasons for this might surprise you, and go well beyond just the fact that academics can tend to be liberal. The study raises some pretty serious questions about how American foreign policy works — and whether it's working the way it should.

What the study found

The researchers asked both groups, public and academic, about whether it was a good idea to go to war in eight different hypothetical cases. Here, as examples, are a question from the study about Iran and another about China:

Would you support or oppose taking military action if it were certain Iran was close to producing a nuclear weapon? Would you support or oppose taking military action to support the government of Taiwan in the event of a Chinese invasion of the island?

Here's a chart of what they found, courtesy of the analysis by Penn's Michael C. Horowitz and UT Dallas's Idean Salehyan, for Political Violence at a Glance. The countries on the left refer to the various scenarios. For example the results for "Taiwan" mean that 36 percent of surveyed experts supported the US going to war in the Taiwan-China scenario above, as did 43 percent of the public:

In every case except Estonia (an interesting exception we'll come back to), the experts are less inclined to use force than is the public.

The numbers on Iran and ISIS are especially stunning: More than 60 percent of Americans support war in those scenarios, but only about 25 percent of experts do.

Academia is known for skewing more liberal than the general public, but political ideology alone doesn't account for the gap between experts and the general public. Horowitz and Salehyan compared conservatives in the public sample to conservative academics, and found that the general trend held: Academic conservatives are "far less likely to support the use of military force" than are general public conservatives.

Liberal academics were also less hawkish than the liberal general public. Horowitz and Salehyan looked at the two cases of humanitarian intervention, Sudan and Myanmar, an issue that often splits the left. They found that liberal academics were less willing to endorse an American-led intervention in those cases than liberals in the public were.

So the data is pretty clear: There is, in the United States, a systematic gap between public willingness to wage war and whether experts think it's a good idea. The big question is why.

Why do scholars and the public disagree on war?

The most compelling explanation for the gap, according to Horowitz and Salehyan, is that expert knowledge is leading them to make different judgments than the public. Knowing a lot of relevant information can pretty substantially alter people's opinions, and it looks like that's what's happening here.

International relations experts also tend to spend a lot of time thinking about working within various theories and schools of thought about how the world works. There's obviously a lot of diversity of thinking within the field, but in general, established international relations thinking suggests that the United States is too inclined to go to war in cases where it might not be effective or a smart use of resources.

This helps explain why experts, with their knowledge of specific case studies and overarching trends, are typically less likely than the general public to conclude that war is a good idea.

This also helps explains the one case in this study where experts are more willing to go to war than is the public: Estonia. (Here's the specific question: "Would you support or oppose taking military action to support the government of Estonia in the event that Russia intervenes militarily in support of ethnic Russians living in Estonia?")

Estonia (unlike Ukraine, or any of the other countries mentioned in the study) is a member of NATO. If Russia were to attack it, all NATO members, including the US, would be treaty-obligated to defend it. That means that in the scenario described, either the US goes to war with Russia to defend Estonia or NATO collapses.

Knowing both that NATO's charter obligates the US to defend Estonia and the consequences of the US not adhering to its obligations, as well as understanding why preserving NATO might be important enough to justify war with Russia, are probably all more common among experts than non-experts. Lacking this information, a person might more easily conclude that Estonia is a very small country not worth going to war with Russia over.

That's fine if the general public doesn't have detailed knowledge about the long-term significance of European security treaties — most people don't need this information to go about their daily lives, any more than international relations scholars have to possess esoteric knowledge about, say, dentistry. But it helps explain the disparity of opinion.

Should we be worried about the divide between experts and the public?

"IR scholars might be tempted to conclude that with greater knowledge of world events, they have more accurate and nuanced views about the appropriateness of force," Horowitz and Salehyan write.

People familiar with the data and history we have about war are dramatically less likely to support going to war

Still, as the two scholars point out, IR researchers have a history of blowing it: Most famously, virtually no one saw the collapse of the Soviet Union coming, a failure the field is still reckoning with. Plus, it's not always clear what IR scholars really know for sure. It's much harder to design rigorous scientific tests in international relations than it is in physics or even economics, and IR scholars disagree with each other a lot.

And yet, IR scholars really have learned some things about the world — the finding that democracies never or almost never go to war with one another is a genuine breakthrough (even if the reasons why it's true are still disputed). And there's a lot of good research on smaller questions, such as whether arming rebel groups is a good way to make a civil war less bloody, that are obviously relevant to American policy.

Where the public-scholar divide becomes most striking is on the issues that dominate the news and political discourse. On key issues of the day — ISIS, Iran, Ukraine — people familiar with the data and history we have about war are dramatically less likely to support going to war than is the general public. This should not be considered a conversation-ending case against war, of course, but it is an interesting insight into how we as a society work through these important foreign policy questions.

Which points to a bigger issue. Policymakers and the international relations academy aren't very good at communicating with each other — but politicians definitely care about what the voters think. That might subtly be tilting America's political conversation in a more hawkish direction.

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