James M. Lindsay is Senior Vice President, Director of Studies, and Maurice R. Greenberg Chair at the Council on Foreign Relations.

As a teaser for next month’s presidential debates, CNN.com’s Global Public Square asked a group of “historians and commentators” to offer their judgments on which presidents enjoyed the most success on foreign policy and which enjoyed the least.  I was lucky enough to be invited to weigh in. GPS posted the picks for most successful foreign policy president yesterday, and it posted the picks for least successful foreign policy presidents today.

I opted for a bipartisan theme with my picks in both categories, selecting Franklin Roosevelt and George H.W. Bush as the most successful foreign policy presidents and Lyndon Johnson and George W. Bush as the least successful.  The other picks for most and least successful foreign policy president also leaned heavily toward presidents from World War II on. (Bruce Jentleson of Duke swam against the tide, applauding Thomas Jefferson for engineering the Louisiana Purchase and booing James Polk for initiating the Mexican-American War.) The tilt toward more recent presidents no doubt reflects the natural tendency to emphasize what we are most familiar with. But it also reflects the fact that foreign policy constitutes a much more significant part of the president’s job after Pearl Harbor than it did before it. Things change when you become a global superpower....