It was late November 1965 when the poet Allen Ginsberg ignited the flower-power movement in Berkeley, Calif., urging protesters against the Vietnam War to greet the police with blossoms, not rocks. A few miles south, at buttoned-down Stanford University, young men would exchange chinos for jeans that academic year. An antiwar activist would become student body president; anti-draft protesters would occupy the university president’s office.


That same November, a newly minted Stanford freshman named Mitt Romney was in Berkeley on a less rebellious mission.


Mr. Romney was on the AxeComm, a school spirit committee. His charge was to keep students at the University of California, Berkeley, from stealing the Stanford Axe, an old lumberjack’s ax awarded to the winner of the universities’ annual football game. He succeeded, infiltrating a cabal of Berkeley students under the pseudonym Tim Yenmor (his name spelled backward), learning their plans and planting disinformation about the ax’s location.


“We were more concerned about protecting the ax from Berkeley students than about the war in Southeast Asia,” said Michael Roake, another freshman who joined Mr. Romney on the mission. “It sounds silly and trivial now. But at the time, we were very earnest.”


The cultural divide that opened that school year on California campuses forever changed some young men. The new Stanford student president, David Harris, was later imprisoned for refusing military service. Some freshmen in Mr. Romney’s dormitory, Rinconada Hall, joined an antiwar commune or fought the draft as conscientious objectors.


Mr. Romney, though, stayed true to his chinos and the Vietnam War, even joining a counterprotest against the occupation of the office of the university president, Wallace Sterling. Forty-six years later, some classmates remember his pro-war stand as principled and heartfelt; others say he merely championed the worldview of his father, George Romney, then Michigan’s governor, a war supporter and a future contender for the 1968 Republican presidential nomination. Still others say he sailed through the most schismatic moral and political issue of that time — and perhaps of any period since in the United States — with neither much angst nor introspection.


On his own for the first time, Mr. Romney finished his freshman year as he began it: conventionally patriotic and faithful to the traditional values of the time. “He was loyal to his family beliefs, his church beliefs and his country’s beliefs without trying, really, to understand what qualifications they had,” said Karl Drake, another Rinconada freshman and an antiwar activist who sometimes clashed with Mr. Romney.


It is unclear whether Mr. Romney’s hawkish Vietnam stance in 1966, when he was 18 years old and first exposed to the larger world, presaged his hawkish foreign policy stance as a presidential candidate in 2012, in which he has promised more confrontational approaches toward China, Iran and Russia than those adopted by President Obama. But just as Mr. Romney’s views on some other issues evolved over the years, his public assessments of the Vietnam War shifted markedly.


His pro-war sympathies at Stanford changed four years later, when he recanted and called the war a mistake. After saying in an interview during his failed bid to unseat Senator Edward M. Kennedy of Massachusetts in 1994 that he had no interest in military service as a youth, Mr. Romney said in 2007 during his first run for the Republican presidential nomination that he had sometimes longed to join the troops in Vietnam.


At Stanford, Mr. Romney was exempt from the draft, holding the 2-S student deferment then given to most undergraduates. He kept it but one year; like his older brother, Scott, Mr. Romney left Stanford early to serve for 30 months as a missionary abroad, as is customary for devout Mormon men.


During that period in France, from 1966 to 1968, he held another draft exemption as a missionary — a controversial one, as critics complained that it disproportionately excluded Mormon men from service.


The Selective Service eventually limited church districts to one religious deferment every six months, sharply reducing draft exemptions in Utah. But in Michigan, where Mr. Romney grew up, the small Mormon population made it unlikely that others competed for the mission that Mr. Romney accepted, said Barry Mayo, a counselor at the time to the district bishop. (After returning from France, Mr. Romney transferred to Brigham Young University and again secured a student deferment.)