THE ODD FORM OF AMERICAN IMPERIALISM:

As ambassador, his big political agenda included overseeing a trade agreement between the US and Vietnam. Peterson also made it his aim to see as much of the country as he could. He visited at least one different province each week, always making a point of stopping by a school, a hospital and a company or factory.

It was on his visits to the overcrowded hospitals that he began to adopt his new cause.

"What I realised in these visits was at least half the people being treated in those facilities shouldn't have been there at all because they were suffering from injuries that could have been prevented," he says.

Raising awareness of health and safety became a major goal of his embassy. In his office, a few blocks from the site of the Hanoi Hilton, Peterson began a programme called Safe Vietnam. He applied diplomatic pressure to the Vietnamese government to improve safety practices.

One of the first areas Peterson focused on was the use of helmets for cyclists and moped riders.

He encouraged the Vietnamese to introduce legislation making helmets mandatory and negotiated a deal with the shipping line APL to donate container space to import them. Today, in contrast to most south-east Asian countries, almost all Vietnamese riders wear helmets - they have become something of a fashion accessory. Peterson says that head trauma in Vietnam has been halved as a result.

In 2000, the Vietnamese Red Cross awarded Peterson their Highest Merit award. Already the owner of a US forces Legion of Merit, the ambassador became one of the few US Vietnam veterans - perhaps the only one - to own a medal featuring the face of Ho Chi Minh.

The following year, Peterson oversaw a landmark mortality and injury study, which showed that the leading cause of child deaths in Vietnam was not infectious disease but accidental injury. The results helped focus the work of a new NGO, The Alliance for Safe Children (Tasc), which Peterson set up with his Vietnamese wife Vi Le (Carlotta having died in 1995).

"We started to look at drowning prevention specifically, because drowning in our statistics was the biggest killer of children in the countries where we had conducted surveys - it was the biggest killer by far," he says.

Tasc estimates one child drowns every hour in Vietnam. In Bangladesh it's one every 25 minutes. Across Asia, the group estimates the death toll to be between 200,000 and 280,000 children per year - around the same as the total number of deaths from the Asian Tsunami in 2004. Nearly half of these victims are toddlers.

Large parts of south-east Asia are covered in rivers and lakes - around 16% of Vietnam, for example - and although children and their parents bathe at dawn and dusk across the region, relatively few people can swim.

"There is a fear of water," says Peterson. "It is not normal for a family to teach the children to swim, because the parents can't swim, because they are absolutely petrified of water."

Working with the Royal Life Saving Society in Australia, Tasc has developed a drowning prevention programme called Swimsafe. More than 300,000 children in Vietnam and Bangladesh have taken the programme and learned basic survival swimming skills.

Although the programme mainly focuses on rural areas, it is also conducted in the Vietnamese port city of Da Nang, which during the war was the location of a major US airbase. Even though the city has beaches on two sides, the training takes place in inflatable swimming pools to allay parents' fears.

Da Nang's government has now committed to ensuring that, by 2020, every child can swim before leaving secondary school.

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