DA NANG, Vietnam — A half-century ago, they were on opposite sides of a nation divided over a distant war.

Suel Jones fought with the Marines in the jungles near the demilitarized zone separating North and South Vietnam. Later, he broke up an anti-war protest in Texas with his fists.

Mark Rudd was a Columbia University campus radical turned domestic militant with the Weathermen, battling those he called warmongers by any means necessary.

In March, they sat on adjacent bus seats in Da Nang traffic, having formed an unlikely but powerful bond. Jones spoke of rejecting his former self, forging a new path.

“What you're describing is word for word my situation,” Rudd replied.

The men had joined a two-week tour of Vietnam sponsored by the anti-war nonprofit Veterans for Peace — part of a group of a dozen veterans, protesters and others who were curious about what the country looks like today.

Jones, 73, who helped lead the tour, had a story a minute as the bus snaked through the mountains on the way to Khe Sanh Combat Base, the Marine outpost that was the site of a disastrous siege in 1968. The hilltop now boasts a museum.

The native Texan never made it up to Khe Sanh when he was here in uniform, but he fought the North Vietnamese Army as an infantryman at Razorback Ridge and The Rockpile along Route 9 and was injured by mortar fire.

Jones came home shaken but still loyal to Uncle Sam. A lot of drugs and booze later, he found himself living in seclusion in Alaska.

“It took me a long time to relearn the moral story of who I was as a human being,” he told Rudd.

The journey brought him back to Vietnam in 1998, where he was shocked at the kind reception he received. He set out to try to reverse some of the damage he and his compatriots had left behind, mainly from Agent Orange and other herbicides that still cause health problems. He has lived in Vietnam off and on since 2000.

For Rudd, 68, the trip was his first to Vietnam. Having grown up in suburban Newark, N.J., he arrived at Columbia University in 1965 as the campus in New York was convulsed with civil rights issues and anti-war activism. He ended up as one of the national leaders of Students for a Democratic Society, an admirer of revolutionaries like Ernesto “Che” Guevara and Ho Chi Minh.

Believing that more drastic and violent action was needed to end the war, Rudd and some friends split from SDS to start the Weathermen. In 1970, three of Rudd's comrades died when a bomb they were building — meant for a military officers' dance — exploded accidentally.

“I didn't plan it, but I knew about it,” Rudd said. He was on the run from the law for seven years before finally surfacing in 1977 to face a variety of charges. He ended up serving probation and moved to New Mexico to teach.

Rudd looks back on those days with regret and wistfulness.

He readily acknowledges the errors of his youth but still gets worked up talking about the heady rush of the era.

He formed a quick bond with Jones as the group made its way through war sites, met with families affected by Agent Orange and watched a demolition of some of the unexploded bombs that still litter the countryside.

The two talked of speaking together someday in the U.S. about how they had both once committed themselves to killing — and now reject it.

“I rebuilt my identity,” Rudd told Jones of his post-Weather Underground years.

Jones replied: “We have more in common than you might think.”