Walker responded by ticking through his recent itinerary of face time with foreign policy luminaries: a breakfast with Henry Kissinger, a huddle with George P. Shultz and tutorials at the American Enterprise Institute and the Hoover Institution.

But then Walker suggested that didn’t much matter.

“I think foreign policy is something that’s not just about having a PhD or talking to PhD’s,” he said. “It’s about leadership.”

Walker contended that “the most significant foreign policy decision of my lifetime” was then-President Ronald Reagan’s move to bust a 1981 strike of air traffic controllers, firing some 11,000 of them.

“It sent a message not only across America, it sent a message around the world,” Walker said. America’s allies and foes alike became convinced that Reagan was serious enough to take action and that “we weren’t to be messed with,” he said.