The Bougainville conflict was a civil war with seemingly no end which resulted in 10 years of bloodshed, marring what was once a Pacific paradise.
The New Zealand Defence Force sent a contingent, but their training in armed combat would be of no use on this deployment.
At the time this remarkable story went largely under the radar, but is now the subject of a documentary, Soldiers Without Guns, due for nationwide release in selected cinemas on April 18.
"At the time we didn't understand the enormity of the situation there. It just dawned on us once we got there - wow, is this what happened here?" says former Navy sailor Aaron Pau.
What he didn't know was that since 1988 Bougainville had been in the grip of a brutal civil war. The operation of the Australian-run Panguna Copper Mine sparked conflict over exploitation, environmental damage, racism and national sovereignty.
Twenty thousand people were killed and almost half of the island's 180,000 population were displaced.
Aaron and fellow naval officer Rata Wairama were teenagers, who were both on the HMS Canterbury and members of their kapa haka group, and the two formed a close bond after their unique mission to Bougainville in 1997.
"We arrived on the island when tensions were still quite high, so they were sort of unsure who we were. We were unsure of what to expect when we landed," says Aaron.
"I think we were quite naïve at the time, being really young," adds Rata.
Although new to the Navy, they soon realised that they had been training all their lives for this radical operation.
"Our military training didn't really come into use, we never used it. It was actually a different type of training that we already had - which was our culture, and our upbringing," says Aaron.
Traditional attempts at brokering peace tried and failed 14 times, and just when all hope was lost, the commander of the Kiwi contingent - Brigadier Roger Mortlock - decided to take a totally unorthodox approach, sending his troops in unarmed, replacing weapons with waiata.
"He said, 'Right, using force hasn't worked, let's try a different approach. Let's bring our culture, let's bring our people in.' Because New Zealand led this mission, as part of the Truce Monitoring Group. I always take my hat off to Brigadier Mortlock. He was ahead of his time back then because it was unprecedented," Aaron adds.
The Bougainvillean locals had never seen anything like it before.
"As soon as we did our kapa haka the walls came down, straight away, they fell in love with us. That was the first time they'd seen kapa haka, the first time they'd seen pukana, these kids were running around for days running around doing pukana for days after that," says Rata.
An ugly history of colonial exploitation had left the Bougainvilleans mistrustful of outsiders. The Māori cultural strategy was the breakthrough needed to negotiate a truce where the peace process had failed so many times before.
"The women are tied to the land just as the Māori culture is," Aaron says. "We have Rangi and Papa, the Earth Mother and the Sky Father. They actually have the same thing, they believe in the same deities. That's why I think that approach worked quite well because these people looked at us and said, 'Wow, we didn't know New Zealanders were like this. We thought they were white-looking people that do the things that the last lot of white people done.'"
Having gained the confidence of the Bougainvilleans, a ceasefire was finally signed in 1998, which saw the end of the decade-long civil war. This not only changed the lives of those in Bougainville, but also for the unsung heroes like the Kiwi kapa haka contingent.
"The world wasn't this safe bubble that I thought it was as a child, so yeah it really did change me," Rata says.
These former sailors' connection to their culture was instrumental in that reconciliation and the part they played has been a highlight in their careers.
"I think it's a story every New Zealander should be proud of, it should be the equivalent of winning the Rugby World Cup. It should be that kind of success story. To know that we saved thousands of people's lives had this war had kept going on," Aaron says.