So how would an Obama administration differ from the Bill Clinton presidency in foreign policy? One way, he said, would be a much greater emphasis on promoting education, health care and development in Africa and other poor regions — not just for humanitarian reasons, but also with an eye to national security.

“If we can’t take what, relative to our military hardware and defense budgets, are a pittance, and put some resources into these areas, we will not be secure,” he noted, adding: “The Marshall Plan was part of a security strategy; it wasn’t simply charity.”

Mr. Obama thumps the White House on trade and foreign investments, like the Dubai ports deal — but he isn’t demagogic in the way that too many Democrats have been. And three years ago, Mr. Obama was quoted in The Chicago Tribune as making hawkish comments about a military strike on Iran, but in the interview he pirouetted and noted that one of the lessons of Iraq is that “being trigger-happy … is a recipe for disaster.” That’s a welcome sign of growth.

So, granted, Mr. Obama lacks the extensive experience at top levels of diplomacy of, say, Dick Cheney or … oh, never mind.

What sets Mr. Obama apart is the way his training has been at the grass-roots rather than in the treetops. And that may be the richest kind of background of all, yielding not just experience, but also wisdom.