March 31 (Bloomberg) -- John McCain's weeklong ``biography tour'' to showcase his half-century of public service will underscore how war dominates his world view.

``McCain's record of noble service is almost a singular asset in his campaign,'' said David Gergen, a professor of public service at Harvard University who advised four presidents. ``The question is whether he can convince people that he will not only keep us safe but also be cautious in using military power.''

The Arizona senator, the son and grandson of admirals and a decorated Navy pilot and prisoner of war, is the most vocal congressional supporter of President George W. Bush's Iraq policies and has all but staked his candidacy on their success. Republican strategists said the party's presumptive nominee must proceed with caution in backing an increasingly unpopular war.

``War-fighting is a divisive topic right now, and what he must hope is that service is not,'' said Tucker Eskew, a former Bush adviser who isn't aligned with the campaign.

McCain knows military heroism alone does little more than gain a candidate an audience.

Before the 2004 election, McCain told Democratic nominee John Kerry that even heroes need a compelling message. He noted that then-Ohio Senator John Glenn, the first American to orbit Earth, was unsuccessful in his 1984 bid for the Democratic presidential nomination even though he was ``a bigger hero than either one of us.''

Dole Example

``We learned that with Bob Dole,'' added Republican pollster Tony Fabrizio, referring to the 1996 presidential candidate and World War II hero.

Jill Hazelbaker, McCain's communications director, said the notion that he might be too prompt to consider the use of force is ``absurd,'' pointing to a March 26 speech to the Los Angeles World Affairs Council.

Even as he presented his case for pressing the global war against terrorism, McCain, 71, said war was ``wretched beyond all description.''

He added, ``I hate war.''

He also parted company with Bush by inveighing against torturing terror suspects, vowing to close the Guantanamo Bay detention camp and signaling a more collaborative approach in foreign policy.

Iraq Presence

Some of his past comments, however, have caused controversy. He was criticized by Democratic candidates Barack Obama and Hillary Clinton for saying in New Hampshire last year that U.S. troops could be in Iraq for 50 to 100 years. He also raised eyebrows with a joke about bombing Iran. In addition, he has used tough rhetoric toward China, Russia and North Korea.

``There's a sense that, with McCain, the way to solve problems is through the military,'' said Gergen, who advised Presidents Richard Nixon, Gerald Ford, Ronald Reagan and Bill Clinton.

Republican strategist John Feehery said McCain's comments reflect ``a fierce patriotism that can manifest in ways that might seem off-putting to some people.''

McCain's life, career and global outlook are informed by war and its consequences.

In his 1999 memoir, ``Faith of My Fathers,'' McCain wrote that one of his first memories was the Japanese attack on Pearl Harbor. His father rushed to his office and McCain, who was 5 at the time, said he ``saw very little of him for the next four years.''

Entranced by Hemingway

In another book, ``Worth the Fighting For,'' McCain recalled being entranced, at age 12, by ``For Whom the Bell Tolls,'' Ernest Hemingway's novel about the Spanish Civil War, which ``made my blood race.''

He also wrote that during the October 1962 Cuban missile crisis, he was aboard the aircraft carrier Enterprise and ``excited as hell'' at the prospect of flying combat missions.

McCain, who served 27 years in the Navy, has deep connections to the military. His ancestors have served in every U.S. war except the 1991 Persian Gulf conflict. One of his sons, a Marine, served in Iraq; a second is at the Naval Academy, which McCain, his father and grandfather also attended.

Mississippi Stop

The first stop on McCain's ``Service to America'' tour today was near a Navy air station in Meridian, Mississippi, that is named for his grandfather. McCain served there as a flight instructor.

In remarks at Mississippi State University, he detailed his ``martial heritage'' while calling the state his family's ancestral home.

``Generations of McCains were born and raised in Carroll County, on land that had been in our family since 1848,'' said McCain.

The brother of his great-grandfather was a major general in the Army who helped organize the draft in World War One. McCain's great uncle served as an artillery officer in World War One. They, along with McCain's father and grandfather, are buried at Arlington National Cemetery.

Such men, McCain said, also instilled in him an appreciation for the need of government to design wise policies on education, job training, taxation, health care and federal spending.

`Life Experience'

``Our strategic objectives will be to tell how Senator McCain's life experience has shaped his values -- values we firmly believe will resonate,'' said Rick Davis, his campaign manager.

McCain endured five-and-a-half years of captivity after being shot down over Hanoi during the Vietnam War. At the time, his father commanded U.S. forces in the Pacific, including Vietnam.

McCain was wounded and the North Vietnamese offered to free him; he refused, saying he wouldn't be put ahead of other U.S. captives, and spent 31 months in solitary confinement.

``There's no question that war -- in one way, shape or form -- has been a constant in Senator McCain's life,'' said Robert Timberg, author of two McCain biographies. ``Perhaps just as powerful, if less obvious, is his sense of honor.''

Building his campaign around his military background may be risky for McCain, particularly if the economy -- which he has acknowledged isn't his long suit -- takes center stage among voters' concerns.

``If the race comes down to national security and foreign affairs, then that benefits McCain,'' Fabrizio said. If the race is about domestic issues, ``then that becomes problematic.''

McCain's challenge hasn't escaped Democrats.

``Democrats are going to do everything we can to make sure we don't have another out-of-touch Republican president who doesn't understand the pressures on working families and wants to keep our troops in Iraq for 100 years,'' said Damien LaVera, a spokesman for the Democratic National Committee.

To contact the reporter on this story: Edwin Chen in Washington at echen32@bloomberg.net.

Last Updated: March 31, 2008 10:32 EDT