Here is an excellent article at The American Interest on the differences between how policymakers and academics think about international relations in the US. Some of these differences carry very important implication for policy. In general, scholars have (not surprisingly) drifted away from practical concerns which limits their influence, author Hal Brands says.
International relations scholars—particularly political scientists—increasingly emphasize abstruse methodologies and write in impenetrable prose. The professionalization of the disciplines has pushed scholars to focus on filling trivial lacunae in the literature rather than on addressing real-world problems.
But practitioners and scholars also take very different positions on some substantive issues. Practitioners are more concerned with American interests, while academics think more as “global citizens” or the stability of the system as a whole. Interestingly, one particular point of difference is attitudes to credibility.
Since the early Cold War, U.S. policymakers have worried that if Washington fails to honor one commitment today, then adversaries and allies will doubt the sanctity of other commitments tomorrow. Such concerns have exerted a profound impact on U.S. policy; America fought major wars in Korea and Vietnam at least in part to avoid undermining the credibility of even more important guarantees in other parts of the globe. Conversely, most scholars argue credibility is a chimera; there is simply no observable connection between a country’s behavior in one crisis and what allies and adversaries expect it will do in the next.
This is clearly extremely important. I have more sympathy with the scholars on this one: many of the worst policy errors have been caused by “domino theories” of credibility.
It is also interesting that there is a gap at all between practitioners and academics in foreign policy. In economic policy, the academics largely captured policy, certainly in the US, in the last two decades. That naturally carries with it a certain style of thinking – and the outcome has been anything but encouraging, with enormous financial crises and volatility.