General Vo Nguyen Giap's last battle for the highlands of Vietnam

In 1954, General Vo Nguyen Giap masterminded a harrowing epic 57-day siege which brought about the crushing defeat of the French empire in Indochina. It was a victory which destroyed the assumption of Western invincibility and inspired anti-colonial struggles all over the world. During the US war Giap was again commander-in-chief, but this time he assumed extra responsibility as the defence minister in Ho Chi Minh's government of North Vietnam.

The amazing supply-line carved out of a 2,000 mile long trail through dense jungle and mountains dubbed the "Ho Chi Minh Trail" was Giap's Initiative. It was to become one of the most bombed roads in the history of warfare. The General also masterminded the final offensive in Spring 1975.

Giap is widely considered to be one of the greatest military leaders of the 20th century - all the more remarkable given that his background was entirely civilian - his early working years were spent as a teacher and a journalist. After the war hard-liners in control of the Vietnamese communist party were jealous of his international stature and intellectual abilities and the war hero was ejected from the politburo in 1982. In 1991 he retired as deputy prime minister.  

The country's most famous soldier is still fighting. This time over the environment.

Now 97, physically frail but still mentally sharp, Giap lives with his wife in an old French colonial house in Hanoi, where he leads a modest existence. He rises at around 5am when he starts his day with breathing exercises before turning into RFI - Radio France International, before listening to the news on Vietnamese stations.

Domestic life is occasionally interrupted by the arrival of various visiting foreign and Vietnamese dignitaries who come to pay their respects. President Lula of Brazil, Hugo Chavez from Venezuela and the South Africa's Thabo Mbeki visited him last year. A number of US politicians have also been to see him, including Robert McNamara his counterpart in the Vietnam War in charge of US Defense Department.

Giap has largely retired from public office apart from holding several honorary roles in associations for Vietnam's war veterans and historians, but the country's most famous soldier is still fighting. This time the battle is over the environment.

The Vietnamese government, eager to keep up the impressive economic growth that was derailed by the global financial crisis, is committed to extracting an estimated 8 billion tonnes of bauxite, the ore which is essential to aluminum production.

Two-thirds of Vietnam's bauxite is to be found in the Central Highlands, a stunningly beautiful and fertile region of thickly forested mountains, coffee plantations and, some argue, an area of enormous eco-tourism potential. There are fears that open-cut mining will destroy vast areas of forest and crops leaving huge deposits of toxic sludge.

Despite Vietnam's long history of conflict with China which briefly invaded the country in 1979, the Chinese aluminum giant Chinalco has been granted a contract for one of the mines. But in January this year, General Giap sent an open letter calling on the government to halt the project.

Giap's stature as a national hero, one-time confidante of late president Ho Chi Minh and one of Vietnam's few untainted politicians is undisputed and the Government realized that they couldn't dismiss him as a mere dissident. Moreover having actively helped Vietnam's ecologists back in the 1980s when he was deputy prime minister, Giap's green credentials are convincing.

According to the scientist, Nguyen Huu Ninh, who was part of a UN team awarded the 2007 Nobel Peace Prize for work on climate change, Giap has a real understanding of ecology. Moreover, "He was our first leader after the war to focus on environmental problems". He has long been fascinated by the green movement. In 1986 a professor returned from a trip to UK with a copy of Schumacher's 'Small is beautiful', one of the Movement's great works and gave it to Giap on a Friday evening; by Monday the General had finished it and was asking for more books on ecology.

So the letter from the 'Green General', which detailed the consequences of the mining proposals in terms of environmental damage, harm to ethnic minorities and even a threat to national security, prompted an unprecedented protest, a rare event in what is still a one-party communist state. It is also rare in a one-party system for such a protest to be reported in the state-owned media. The general's intervention prompted 135 intellectuals to sign a petition to the Vietnamese National Assembly calling for a halt to the project.

In the face of the outcry, Prime Minister Nguyen Tan Dung, who had described the exploitation of the bauxite as "a major policy of the party and the state", felt he had no choice but to backtrack. Last month, after a hastily convened seminar on the environment, he agreed to scale back the development until a full assessment of the possible environmental impact could be made.

Now opponents have questioned the mines' economic feasibility, given that bauxite processing requires a lot of water and access to cheap electricity, and Vietnam is facing shortages of both. In addition to the environmental concerns, some critics have complained about the presence of hundreds of Chinese workers in the strategic Central Highlands.

Amid the flurry of criticism, which was even joined by his Environment Minister, Dung has now frozen work on one bauxite mine, though he has permitted Chinalco to proceed with another.

General Giap may not win this battle outright but, as always, he is putting up a ferocious fight. ·