JD Hamel was a high school senior in an Ohio steel town when the United States invaded Iraq in 2003. The future senator and nominee for vice president, who uses Vance for his surname now, joined the Marines a few weeks later confident, he later recalled, that freedom and democracy would follow.

But his optimism was short lived as the war, deemed necessary by President George W. Bush after spurious intelligence indicated a dire threat to U.S. security, quickly proved a deadly quagmire instead.

“My entire life has been influenced and affected by the decisions we made a month before I enlisted,” Vance said last year in a speech at the conservative Heritage Foundation. He lamented how those who were “the most wrong” about Iraq “suffered no consequences.” The U.S. foreign policy establishment, he asserted, “has learned zero lessons from what is perhaps the most unforced and catastrophic error in the history of this country.”

Those comments are emblematic of the antiestablishment views Vance, 40, has promulgated before and since becoming Donald Trump’s running mate. And while his military service represents only a brief period of his early adulthood, he and his political opponents both have seized on his service in the early days of his addition to the ticket.

If elected, Vance would become the first to serve at such a senior level from among the generation of men and women who went to war after 9/11. He spent four years in the Marines, from ages 18 to 23, deploying once to Iraq for six months in his capacity as a public affairs specialist, a job that entailed writing news releases, taking photos and interacting with journalists. He did not face combat.

Vance’s rhetoric, however, has puzzled some who served with him, as he has shifted from a moderate Republican sharply critical of Trump just a few years ago to a hard line ally now who has echoed the former president’s falsehoods about the 2020 election and made demeaning comments about “childless cat ladies” and prominent Democrats.

Cullen Tiernan, who served with Vance, said he was not interested in assessing Vance’s statements about past elections, adding “a lot of this election chatter is looking backwards.” Asked if he intends to vote for his friend, Tiernan, who identifies as left-leaning, said he was undecided.

“I love JD, I really want to vote for him, but it’ll take me some time to get there. I want to hear what Harris has to say,” he said. “I’m going to take my time and give it a lot of deep thought.”

Some Democrats have sought to minimize Vance’s military record because he saw no combat and argued that his allegiance to Trump is an affront to the Constitution and core values of honor, courage and commitment that every U.S. Marine promises to uphold.

Vance’s former military colleagues defended him against such allegations that his service record should be left out of criticism of his politics. Shawn Haney, a retired Marine officer whom Vance has praised for her mentorship during those years, said she doesn’t agree with “much of his current politics.”

Yet Haney she is able to “separate the person from the candidate and have those unconditional feelings of pride for someone that I have served with, mentored, and considered a friend for almost 20 years.”

Vance, through a spokesman, declined to comment for this article.

A transformation

In his 2016 best-selling memoir “Hillbilly Elegy,” Vance wrote that he first considered joining the Marines at the suggestion of a cousin who had served. He was interested in attending college, he wrote, but had a spotty high school transcript and worried he would struggle with the debt and lack of structure that college life would bring.

In September 2003, Vance shipped off to boot camp in Parris Island, S.C., where a team of frothing drill instructors hounded him and the other recruits, barking orders and pushing them to their physical and emotional limits. He dropped 45 pounds in that time and emerged from the experience with a newfound confidence, his book says.

After graduating from entry level training, Vance went home to visit family and friends in Middletown, Ohio. He saw a “world of small expectations” and “learned helplessness,” he wrote — people who believe their choices have no effect on their lives. Marines are taught the opposite.

When Vance arrived at Cherry Point, an airfield in North Carolina, to start his first assignment, he was, like most new to the military, not a “worldly guy,” said Wil Acosta, who supervised him. Acosta recalled how more seasoned Marines in their unit felt protective of him and once imparted their counsel to ensure Vance wouldn’t get scammed by the high-interest loan car lots that ring a lot of bases.

Vance was reserved at first, said Curt Keester, who also served with him at Cherry Point. Eventually, though, Vance opened up, sharing stories about his older sister, Lindsay Ratliff, her children, and his colorful grandmother, known as “Mamaw.” He has described her as a gun-toting, foul-mouthed “hillbilly” who stepped in as his mother struggled with drug addiction. Keester said Vance spoke less about his mom in those days.

Tiernan said Vance loved reading and was a fan of the authors Ayn Rand, C.S. Lewis and J.R.R. Tolkien. In their free time, they enjoyed visiting the beach, watching football at Buffalo Wild Wings, and playing poker.

‘Affected deeply’ in Iraq

Vance deployed to Iraq from August 2005 to February 2006, and was posted at Al-Asad air base in the western part of the country. The American public had largely soured on the war as sectarian bloodshed soared and it became clear the United States could not easily disentangle itself from the conflict.

Shortly after he arrived, Vance wrote on a blog that he was “a little homesick, but mostly happy to be here and finally contribute, even if only a small part, to our country’s mission.” A spokesman confirmed the blog’s authenticity.

In the weeks before Vance’s deployment, Bush addressed the nation attempting to rally support by describing Iraq as part of a broader war against terrorism. Months later, the president acknowledged that “much of the intelligence” cited by the administration to make the case for its occupation was “wrong.”

While overseas, Vance lived in trailer-like containerized housing, rooming with Tiernan and spending hours watching DVDs sent from home or pirated and sold to them in base shops, his friends recalled.

The public affairs Marines did much of their work at desks, but they sometimes left the relative safety of their base to capture the stories of service members more directly in harm’s way. Vance’s articles from Iraq appear under the byline James D. Hamel, his legal name at the time. Among them are interviews with pilots and an account of a visit by the Marine Corps’ top general.

Vance, in his book, wrote that he was “lucky to escape any real fighting” but “affected deeply” by a day in which he encountered an Iraqi boy whom he handed an eraser, prompting the boy to become “overjoyed” at the small gift despite attending a school without running water.

While Vance wrote that he doesn’t believe in “transformative moments,” the exchange was “pretty close.” He had long resented his own family’s circumstances, he added, and changed his perspective as he observed what it was like to come of age in war-ravaged Iraq.

“I began to appreciate how lucky I was: born in the greatest country on earth, every modern convenience at my fingertips, supported by two loving hillbillies, and part of a family that, for all its quirks, loved me unconditionally,” Vance wrote.

Rep. Seth Moulton (D-Mass.), a former Marine infantry officer who deployed to Iraq four times, has made perhaps the sharpest attack on Vance’s service record. Speaking in July on the left-leaning “Pod Save The World” podcast, Moulton said Vance “didn’t do much fighting” during the war and “doesn’t exactly uphold Marine values.”

“I consider him one of the biggest hypocrites in Congress,” Moulton said. “Someone who wrote a book completely contradicted by his candidacy. Someone who assailed Trump before he became a sycophant. This is a man who does Trump’s bidding, and I suspect that is the sole reason that he picked him, or at least the most important reason.”

Haney, the retired officer who supervised Vance, expressed frustration at attacks on his military record. His politics and comments are fair game, she said, but he volunteered to serve at a tense and dangerous time, and did so honorably, she added.

Haney said that when Vance returned to Cherry Point from Iraq, she selected him to be a representative to local media, even though his rank at the time, corporal, was junior to the officer typically assigned to the position. He was the “obvious choice,” she said, because he had shown he could learn on the fly and handle the responsibility, she recalled.

Vance, Haney said, appeared then to be a conservative and showed an interest in politics, noting that he also wanted to hear others talk about their own views.

“He probably always had a healthy dose of cynicism,” she said. “But he also had a good ability to assess, and he understood he had a limited view.”

‘He calls it like he sees it’

After his enlistment ended in 2007, Vance attended Ohio State University and then Yale Law School, where he sharpened his views of an America divided between liberal elites and more conservative masses, which he later explored in his book that vaulted him to fame.

Vance and his fellow Marines have kept in touch, shooting texts back and forth and exchanging holiday cards. A few attended his wedding in Kentucky in 2014. Three years later, Vance and several of the Cherry Point Marines gathered in North Carolina for a reunion, Keester said.

After Trump selected Vance as his running mate, Tiernan sent a congratulatory text. “Thanks dude,” he replied, Tiernan recalled.

Some of Vance’s friends see shades of his Marine Corps experience poking through in his foreign policy views, notably his aversion to how much money the United States spends abroad — particularly in Ukraine. In an April speech on the Senate floor, he said he realized after deploying to Iraq that the premise of that war was “a lie” and drew parallels to Washington’s military and financial support for Kyiv now.

“It’s the same exact talking points 20 years later,” Vance said, though the situation remains much different, with an American invasion in Iraq leading to a years-long insurgency and a Russian assault on Ukraine prompting the United States to deliver weapons and other resources without sending its own troops.

Vance has had a rocky debut as Trump’s running mate, drawing unwanted scrutiny to old, controversial comments. His critics, including some Republicans, have questioned whether Vance is the right running mate for Trump, and whether the Trump campaign spent enough time vetting him.

Vice President Harris, who has replaced President Biden atop the Democratic ticket, has assailed Vance for his shift toward Trump, claiming last month that he’d be “loyal only to Trump, not to our country.”

Vance responded during a campaign event days later in Michigan, a crucial battleground. “Well, I don’t know, Kamala,” he said. “I did serve in the United States Marine Corps and build a business. What the hell have you done other than collect a check?”

Tiernan said Vance’s observations as a young man have provided a vantage from which he can scrutinize the nation’s military and political leaders.

“He calls it like he sees it,” Tiernan said. “He can question it from a place of personal experience.”

Aaron Schaffer contributed to this report.