He will speak at Monday’s Long Tan ceremony at the Cenotaph.

While he was not there for Long Tan, the now legendary Tet offensive took place the year he arrived.

Dr Doust arrived in Vietnam in 1967 the year after the battle of Long Tan and completed an eight-month stint in an Australian surgical team treating civilians.

He was one of around 360 Australian doctors who volunteered for the Department of Foreign Affairs program to send medical help to the war-torn country.

“It was a dreadful battle fought in a rubber plantation,” he said. “It’s a frightening place to be even without people shooting at you. It’s a dark gloomy place with trees in rows as far as the eye can see, obscuring the people you are fighting.”

His surgical team was based in the city of Long Xuyen and just escaped being overrun by the Viet Cong and North Vietnamese armies. Towns adjacent on the Cambodian border and on the Mekong Delta were captured.

The other two Australian surgical teams were also safe as they were situated on the well-protected former base of the French Foreign Legion and the very busy main American Air Force base.

Highlights included a visit from former Prime Minister Gough Whitlam.

When Mr Whitlam requested a photograph of the landscape from a badly shot-up water tower, Dr Doust volunteered to climb up the crumbling ladder to get the shot before handing back Mr Whitlam his camera.

A few weeks later he met US presidential candidate Robert Kennedy who days later was assassinated at the Democratic National Convention in Chicago.

While harrowing, his time in Vietnam was an adventure and he learned respect for the Vietnamese people.

“The Australian easy-going attitude made things easier,” he said. ‘We took a laissez-faire approach and treated everyone the same, which was different possibly to that taken by the American teams who were looking for the people supporting the VC.”