In the first months of the Obama presidency in 2009, Chuck Hagel, who had just finished two terms as a U.S. senator, went to the White House to visit with the friend he had made during the four years they overlapped in the Senate.

So, President Barack Obama asked, what do you think about foreign policy and defense issues?

According to an account that Hagel later gave, and is reported here for the first time, he told Obama: "We are at a time where there is a new world order. We don't control it. You must question everything, every assumption, everything they" — the military and diplomats — "tell you. Any assumption 10 years old is out of date. You need to question our role. You need to question the military. You need to question what are we using the military for.