On October 17, the Brookings Institution’s Project on International Order and Strategy hosted two of the most prominent thinkers on American grand strategy to discuss whether Washington should remain forward-leaning in its posture, or if it should adopt a more restrained approach to global engagement.

The event was moderated by Brookings Foreign Policy Fellow Jeremy Shapiro, and featured a debate between Brookings Foreign Policy Senior Fellow Robert Kagan and Barry Posen, Ford International Professor at Massachusetts Institute of Technology.

Kagan argued that the United States has an enduring responsibility and capacity to shape the world order and must remain actively engaged abroad to prevent the international order from collapse. Posen, on the other hand, warned against American overreach in foreign policy and urged Washington to embrace restraint, focusing on its own national security interests and limiting engagement – particularly military - abroad.

In their discussion of the Middle East, both scholars sought to define American regional interests with greater precision. Posen argued that “affective” relationships, such as those with Israel, do not explain the U.S. defense budget dedicated to the region or contingency plans for the region. Posen also disputed the view that oil is the primary driver of U.S. regional policy, suggesting that threats to major suppliers could be managed with a less robust regional security commitment than Washington has traditionally maintained.

Kagan argued that President Obama is more intellectually inclined toward Posen’s strategy of restraint than most of his predecessors, and yet he too has been drawn into the Middle East. “It can’t just be pure stupidity that has had the United States involved in the Middle East as consistently as it has been for almost 70 years now, taking the place of the previous powers that had been involved in the Middle East,” he said.

Posen discussed U.S. efforts against the Islamic State group (also called ISIS or ISIL). He noted that President Obama’s rhetoric on ISIS has gone beyond what is prudent, describing the strategy as one of “containment that’s augmented by the promise of future counter-offensives and destruction.” Washington’s current strategy, Posen argued, has demobilized allies by enabling them to skirt responsibility for the crisis.

Posen and Kagan differed in their interpretations of the track record of American interventions in the region. Posen criticized American understanding of the causes and effects of intervention, saying that it is easier to oust a government than to generate internal consensus or transform a country into a stable democracy. By contrast, Kagan argued that the U.S. has never invaded a Middle Eastern country with the purpose of rearranging domestic politics.

There was little discussion of terrorism and nuclear proliferation, though Posen identifies these two threats as major items on which the U.S. should remain engaged. More information about Posen’s arguments can be found in his new book, Restraint: A New Foundation for U.S. Grand Strategy (Cornell University Press, 2014). Kagan’s argument for continued pre-eminence and engagement in grand strategy can be found in his influential May 2014 New Republic essay “Superpowers Don’t Get to Retire.”