When it comes to putting the starch back into the flaccid spines of some post-Sept. 11 Americans, Sen. John McCain (R-Ariz.) just might be the man for the job.

After all, McCain, who this month releases “Why Courage Matters: The Way to a Braver Life,” spent nearly six years as a prisoner of war in North Vietnam.

But it’s not his own experience in the hell of the infamous “Hanoi Hilton” that McCain draws upon in his latest literary undertaking.

Instead, McCain looks to the experiences of others to illustrate his central point: that courage is displayed not by an absence of fear, but by the overcoming of fear.

“Why Courage Matters,” written at the suggestion of his creative editor, Jon Karp, marks the third time McCain has collaborated with his longtime aide, Administrative Assistant Mark Salter. Their earlier books include “Faith of My Fathers” and “Worth the Fighting For: A Memoir.”

Interpolated between their riffs on courage are the stories of those men and women whom they believe serve as exemplars of courage. These range from a former Green Beret who endured unimaginable danger and physical injury to rescue his comrades during the Vietnam War to a pro-Democracy leader in Burma whose stoic struggle against a dictatorial regime has continued for decades.

Closer to home, the book highlights McCain’s Congressional colleague Rep. John Lewis’ (D-Ga.) bravery in the face of resistance to his civil rights activism in the early 1960s, as well as the ordeals of Salter’s father, Chester Salter Jr., on the battlefields of North Korea.

Despite the book’s thematic resemblance to then-Sen. John F. Kennedy’s (D-Mass.) 1957 “Profiles in Courage,” McCain says it has little relationship to the slain president’s earlier work, which focused on the political heroism of Kennedy’s historical Senatorial colleagues.

“The inspiration for the book is obviously 9/11 in this respect that there were so many people who had their lives dramatically altered and some at least in my opinion allowed the terrorists to dictate how they conducted their lives,” says McCain, holding forth from his office on the second floor of the Russell Senate Office Building on a recent Thursday evening.

When it comes to getting this point across, he and Salter do not mince words.

“Get on the damn elevator! Fly on the damn plane! Calculate the odds of being harmed by a terrorist! It’s still about as likely as being swept out to sea by a tidal wave. Watch the terrorist alert and go outside again when it falls below yellow,” they write. “Suck it up, for crying out loud. You’re almost certainly going to be okay. And in the unlikely event you’re not, do you really want to spend your last days cowering behind plastic sheets and duct tape? That’s not a life worth living, is it?”

As to who deserved credit for the widely disseminated quote, when questioned, McCain quietly points to his 49-year-old staffer, who he said is responsible for “90 percent of the work” on their trio of books.

“But it’s written in John McCain’s voice,” Salter quickly counters. “He speaks like that all the time.”

And after 15 years as an aide to McCain, Salter should know a thing or two about channeling the three-term Republican Senator.

“Everything I’ve written in my life, I write in his voice — speeches, op-eds, books,” Salter says. “When we worked on the first book … [it was] hours and hours and hours of cassette tapes with his voice in my [ear]. So you really learn to write in the rhythm that he speaks in.

“There’s a danger of having a complete psychotic breakdown, having totally lost your personality,” he laughs, noting that the two men spent more time together than with their families.

“If you’ve had a million conversations as we’ve had … over 15 years, it’s not difficult to communicate one’s thoughts and ideas,” adds McCain.

Salter, who previously worked as an aide to former U.S. ambassador to the United Nations Jeane Kirkpatrick, was first introduced to McCain on the floor of the 1988 Republican National Convention in New Orleans by the Senator’s then-press secretary, Victoria Clarke. After a brief stint as a periodic speechwriter for McCain, Salter joined the staff as foreign affairs legislative assistant the following year before rising to his current post.

With graduation season right around the corner, expect to see McCain touch on what he and Salter have dubbed “the enforcing virtue” at commencement addresses across the nation.

This spring, the Grand Canyon State’s senior Senator is slated to speak to the graduating classes of the University of Florida, University of Southern California and Northern Arizona University, Salter said.

McCain, who in recent weeks has been the subject of much speculation as to whether he would consider joining the ticket of the presumptive Democratic presidential nominee, Sen. John Kerry (Mass.), said he did not write the book as a potential platform for a return to presidential politics, as Kennedy was widely viewed to have done with his Pulitzer Prize-winning tome in the late 1950s.

Asked to confirm that he had indeed ruled out a vice presidential bid, McCain looked down and chuckled somewhat ambiguously, before echoing his aide’s words: “You can say that categorically.”

McCain will be on hand to sign copies of his book at 12:30 p.m. April 15 at Trover Shop on Capitol Hill.