As Barack Obama prepares to vacate the Oval Office after two terms, he has earned an odd distinction: the United States has been at war every day of his tenure, a record unmatched in American history. The next president’s performance as commander in chief may well dwarf the importance of any domestic-policy position he or she takes. In fact, the central role of immigration and trade in the current presidential contest suggests that there is no longer any easy way of separating foreign from domestic policy. A serious consideration of the current state of the world, however, has been largely absent from this campaign season. What are the greatest challenges to the current international order? How can the world — and the next U.S. president — meet these challenges? Is military intervention still an appropriate response? If not, what alternatives are available? This summer, Harper’s Magazine convened a panel of experts in international relations to discuss the pressing questions that have not yet been asked. The conversation was moderated by Andrew J. Bacevich, a military historian and a contributing editor of the magazine.