Thirty years after
hostilities ended between the US and Vietnam, relations remain strained by
one of America's most notorious actions, the use of the chemical Agent
Orange.
The Vietnamese believe that
the powerful weed killer - the use of which was intended to destroy crops
and jungle providing cover for the Vietcong - is responsible for massively
high instances of genetic defects in areas that were sprayed.
Nguyen Trong Nhan, from the
Vietnam Association Of Victims Of Agent Orange and a former president of
Vietnamese Red Cross, believes the use of Agent Orange was a "war crime".
He told BBC World Service's
One Planet programme that Vietnam's poverty was a direct result of the use
of Agent Orange.
"They are the poorest and
the most vulnerable people - and that is why Vietnam is a very poor
country," he said.
"We help the people who are
victims of the Agent Orange and the dioxins, but the capacity of our
government is very limited."
Contaminated areas
Campaigners such as Mr
Nguyen believe they have been left with little choice but to resort to
legal action, and in 2004 took the chemical companies that produced Agent
Orange to court in the US.
But last month an American
Federal District Judge dismissed the case on the grounds that use of the
defoliant did not violate international law at the time. An appeal has
been lodged against this decision.
The US sprayed 80m litres
of poisonous chemicals during Operation Ranchhand. There were many Agents
used, including Pink, Green and White, but Agent Orange was used the most
- 45m litres sprayed over a 10th of Vietnam.
It was also used - mostly
in secret - over parts of neighbouring Cambodia.

It's not going to go
away, because it affects a huge number of people in Vietnam
Andrew Wells-Dang, Fund for Reconciliation and Development
But Agent Orange in
particular was laced with dioxins - extremely toxic to humans. Dioxins
accumulate in the body to cause cancers. Anyone eating or drinking in
contaminated areas then receives an even higher dose.
Spraying stopped in 1971,
after more than 6,000 missions and growing public disquiet.
But the ground in many
areas of Vietnam remains contaminated by Agent Orange. A number of people
in these areas believe they are victims of the chemical.
One woman said the
herbicide had caused a skin disease which gave her "great suffering".
"If the US and Vietnamese
governments could care for people like me, that would be comforting," she
added.
Another man said his legs
have "wasted away" as a result of Agent Orange.
"When I realise I have been
contaminated with poisonous chemicals, and the US government hasn't done
anything to help, I feel very sad, and it makes me cry," he added.
"Now I always get severe
headaches. My first child has just died - he had physical deformities. The
second one is having headaches like me."
Cancers and disease
Food and supplies are still
delivered to victims of Agent Orange. Many were not born when the US
sprayed the area - but there is strong evidence the chemicals are still
having an effect.
A disproportionately large
number of children in the areas affected are born with defects, both
mental and physical. Many are highly susceptible to cancers and disease.
And Vietnamese doctors are
convinced Agent Orange is to blame.

"This is due to the US
sprayings," said Dr Hong Tien Dong, village doctor who has lived in the
area all his life.
"Before, in this area, the
environment was quite clean.
"Now it has become like
this."
In the late 1990s, a
Canadian study tested soil, pond water, fish and duck tissue, as well as
human blood samples, and found dangerously high levels of dioxin
travelling up the food chain to humans.
Dioxin concentrations have
been found to be 13 times higher than average in the soil of affected
areas, and, in human fat tissue, 20 times as high.
A Japanese study, comparing
areas sprayed with those that were not, found children were three times
more likely to be born with cleft palates, or extra fingers and toes.
There are eight times as
many hernias in such children, and three times as many born with mental
disabilities.
In 2001, scientists found
that people living in an Agent Orange "hotspot" at Binh-Hoa near Ho Chi
Minh City have 200 times the background amount of dioxin in their
bloodstreams.
Humanitarian opportunity
America "normalised"
relations with Vietnam 10 years ago, and the country has now embraced the
free market.
No representative of the US
government in Vietnam would talk to One Planet about Agent Orange.
However, in 1984, chemical
companies that manufactured the Agent paid $180m into a fund for United
States veterans following a lawsuit. They did not, however, admit any
wrongdoing.
Meanwhile in 2004 - at the
same time Mr Nguyen first brought his lawsuit - a joint-US-Vietnamese
project to examine the long-term genetic impact of Agent Orange was
cancelled.
Some Americans in Vietnam
fear that the legacy of Agent Orange is overshadowing the new friendship
between the two countries.
"Many of the other
obstacles have been dealt with - trade and exchange and diplomatic
relations," said Andrew Wells-Dang, from the Fund For Reconciliation And
Development - an American organisation set up in the 1980s with the aim of
improving relations between the countries.
He pointed out that the US
has provided funding for clearing mines that it dropped on Vietnam during
the war.
"We think the US should do
the same with Agent Orange," he added.
"It's not going to go away,
because it affects a huge number of people in Vietnam.
"We would see this as an
opportunity for the US to take humanitarian action so that it doesn't
become an obstacle between the countries."