• More than 3000 New Zealand military and civilian personnel served in Vietnam between 1963 and 1975.
• At its peak in 1968, New Zealand's military force numbered only 548.
• 37 died in active service, plus two civilian deaths, and 187 wounded.
Some say that time heals all wounds. Old soldiers disagree. For them, the scars of war are always there.
"It's just near the surface somewhere," says Vietnam veteran Chris Mullane.
It's been nearly 50 years since he crept through the thick, swampy jungles and paddy fields hunting Viet Cong.
But loud noises, sudden bangs, a car back-firing, can bring it all back. And then there's the dreams. Nightmares, really.
For 69-year-old Mullane, it'll never go away.
"You might think it has, but it sneaks up on you. And something can just kick it over."
A fresh-faced combat infantry platoon commander with 35 young lives under his guidance in 1971, ambushing and patrolling, uncovering underground bunker networks, he never lost a man in battle.
In the decades since, however, almost half of his war buddies have died.
Some succumbed to cancers likely linked to Agent Orange, the controversial use of toxic chemicals by the US military to defoliate large areas of jungle.
Others took their own lives. Mullane believes that can be linked to the war too.
"When you're on operations, you're into the next patrol, the next ambush. You've got to stay alert, you can't really spend a lot of time reflecting," Mullane says.
"I think that's what happens, people bottle that up. I've had a couple of my guys, unfortunately after we've come back, commit suicide, and some of that would've been the build up of the experience, and no emotional outlet. There's no doubt about that."
This week, Mullane remembers them all.
Along with 34 other New Zealand veterans of the Vietnam War, he is attending memorial services in Canberra to mark the war, and tomorrow will commemorate the 50th anniversary of the Battle of Long Tan - the bloody fight that has become the focal point for commemorations on both sides of the Tasman.
Mullane hasn't been back to Vietnam since his days with Victor 6 Company, 4th Battalion, Royal Australian Regiment (4 RAR) New Zealand (Anzac) Battalion. He thinks he'd now like to.
Former Royal New Zealand Artillery officer Barry Dreyer never wanted to return either. He lost a best mate there - one of 37 New Zealanders who died on active service.
He and Peter Williams had been through a lot together. They trained together before landing in Vietnam in May 1966, and commanded artillery batteries alongside each other at the Battle of Long Tan.
The 6th Battalion Royal Australian Regiment's 108-man D Company found themselves suddenly surrounded by up to 2000 Viet Cong in a rubber plantation near the village of Long Tan near Australia's taskforce base at Nui Dat on the afternoon of August 18, 1966.
A fierce gun battle broke out as the Viet Cong attempted to surround the badly-outnumbered Australians.
"We could hear and see it, we knew it was bad. Whenever [the Australian officers] keyed their mic, all you could hear was machineguns and explosions," Dreyer recalls.
A severe thunderstorm - the worst Dreyer saw during his 16 months in country - made conditions even tougher for the gun batteries attempting to fire shells with pinpoint accuracy to keep the enemy at bay and give the Aussies a fighting chance at getting out alive.
"It was a period of very intense activity, in awful conditions, with ammunition running out on the gun line, with cooks, bottle washers, visitors, all working hard to keep the ammunition supply up the guns. We all knew it was a terribly one-sided fight," Dreyer says.
As dusk came, and Dreyer worried about running out of ammunition, the enemy finally withdrew back into the jungle.
The Australians lost 18 men. But it could've been much worse if it wasn't for the accurate and relentless barrage put down by Dreyer and his mates. An estimated 245 members of the Viet Cong were killed.
Afterwards, Dreyer returned to 161 battery as a gun position officer where he remained for the next 11 months, before returning home in September 1967.
Williams, a married father of two, was killed in action on Valentine's Day 1967. He was due to fly home but had volunteered for a final patrol after they'd found themselves a man short. He never came back, killed by a booby trap.
It was a devastating blow for Dreyer.
They were "very close", having shared a tent together, and gone through the war side by side.
For years Dreyer's family had encouraged him to return to Vietnam, but he avoided it.
"Every time I flew over Vietnam, heading somewhere else, it still looked as grubby and dirty and filthy as I remembered it. I really had no great desire to go back at all. But the family convinced me that I should," he said.
Dreyer, a 71-year-old father of three, with five granddaughters, who lives in Howick with wife Judy, returned to Vietnam four years ago and laid poppies at the spot Williams was killed.
"It was sort of cleansing. It was not a load off my chest, but I was very pleased that I did it," he said.
Mullane, a father-of-five and grandfather who now lives in the North Shore suburb of Bayswater, is now considering such a cathartic pilgrimage.
He has been an active campaigner for veterans rights in recent decades.
Vietnam was an unpopular war with the New Zealand public. There were widespread protests through the country during the war.
When the troops - all professional soldiers who volunteered for service - came home, they were encouraged by the Army to travel in civilian clothes.
Many were shunned socially, and suffered discrimination while job-hunting.
While studying at Auckland University after he returned home, Dreyer's fellow students refused to sit in lectures with him.
Many soldiers struggled to return to civilian life. Mullane says the Defence Force is better today at recognising post-traumatic stress disorder (PTSD) and helping its personnel deal with the mental and emotional stresses that comes from experiencing war.
"They're more open about it. In the old days, it wasn't manly," he says.
"When you go back Second World War, First World War, Malaya and so on, you just didn't say anything. You might be suffering from some sort of mental or emotional stress and you didn't say anything, you kept it in, and that's probably the worst thing that can happen because it's churning around inside you.
"But it's very unpredictable. Some people didn't appear to be affected by that at all. Many guys fit back into society and be very successful in business or whatever career they move back into. Others, very badly, and hence the suicides."
Dreyer also has mates who have "suffered terribly" with PTSD.
Both Mullane and Dreyer have been looking forward to the 50-year reunion. A chance to meet up with old mates, share a beer, and some yarns.
It's also a chance to remember those who died in the war, and since.
Mullane especially wishes he could be reunited with his old radio operator, Private G.J. 'White Trash' Murphy'.
The last he heard, Murphy was living wild "down south" deep in the native bush, without electricity or running water. He'd heard that he occasionally ventures out of the bush to a country hotel to get cleaned up and eat some hot food.
Mullane says the friendships forged in war lasts a lifetime, regardless of time spent apart.
Dreyer, who today (Wednesday) presented a sculpture of a Vietnam gunner, by sculptor Matt Gauldie, to the Royal Australian Infantry Corps to commemorate 100 years of combat support, also treasures the special life-long camaraderie.
"One of the guys I went away with, he was a year or two younger than me, I've just emailed him this morning and he's coming up here to stay with me, and this is from 50 years ago. So you actually end up being a very tight-knit group and you're mates for the rest of your life."
TIMELINE - NEW ZEALAND's VIETNAM WAR
• 1963: New Zealand Prime Minister Keith Holyoake agrees to provide "non-combatant" troops under pressure from the US.
• April 1963: NZ civilian surgical team arrives in Vietnam.
• June 1964: 25 Army engineers sent to South Vietnam to build roads and bridges.
• July 1965: 161 Battery Royal New Zealand Artillery (RNZA) arrives in Vietnam.
• June 1966: 161 Bty comes under operational control of 1st Australian Task Force (1ATF) at Nui Dat.
• August 1966: 161 Bty involved in the Battle of Long Tan.
• March 1968: NZ infantry companies integrate with 2RAR to form 2RAR/NZ (Anzac) Battalion at Nui Dat.
• December 1971: Last combat companies withdrawn.
• April 1975: NZ Ambassador evacuated from Saigon; last RNZAF flight out of Vietnam.
- Source: New Zealand History