From ragtag volunteers with home-made shotguns to stealth frigates, telecoms conglomerates and golf courses -- the Vietnam People's Army has transformed since its victory over the French six decades ago.

"We had nothing: some homemade rifles and explosives, some anti-tank bombs so rudimentary they killed the soldier who detonated them," said military historian Major General Vu Quang Dao.

"It was a victory of strong will," he said ahead of the 60th anniversary on May 7 of the defeat of the French forces at Dien Bien Phu that shocked the world and helped end European colonialism.

Vietnam is now one of the top spenders on defence in Southeast Asia as it seeks to safeguard territorial claims in the contested South China Sea.

"Their procurement of modern military systems is really accelerating to a tremendous degree," Jon Grevatt, Asia Pacific defence industry analyst with IHS Jane's, told AFP.

"It is very clear where that procurement is aimed: securing its offshore assets, securing its territory, its exclusive economic zones, and of course it is aimed at addressing any threat from China."

In acquiring hardware -- mainly from Russia -- and forging strategic partnerships with countries from Germany to South Korea, Vietnam's army is becoming "more professional, more efficient, more effective," Grevatt said.

- Opaque military budget -

IHS Jane's estimates the country's "opaque" defence procurement budget at $1.26 billion for 2014 but says evidence suggests these figures may underestimate the true scale of spending.

"It is supplementing its defence procurement budget through off-budget revenues: oil and gas, nuclear," Grevatt said.

Over the past three decades the Vietnam People's Army has built up a network of businesses and corporate interests that generate significant revenue.

The army has always been "a crucial force in Vietnam's politics," but as the communist country embraced economic reforms in the late 1980s, the nature of the army's role changed, said Professor Jonathan London at City University of Hong Kong.

"The military has taken an active role in the market economy," he said.

Both the army and individuals within it have "been able to cash in on privileged access to land, capital, and permissions to seize market opportunities."

In Vietnam, the military is far more of a presence than in many western countries -- there is still national conscription and the army is in charge of mandatory "defence education" courses at universities.

The army owns hotels, golf courses, television stations, newspapers and even one of the country's largest telecoms companies, Viettel, which has expanded overseas in countries from neighbouring Cambodia to Haiti.

- Golf courses and hotels -

Over the course of Vietnam's decades of war, the military ended up holding vast tracts of land, many of which have not been handed back to civilian control but are developed, often controversially.

The army is currently embroiled in a dispute over the construction of a golf course on prime land -- owned by the defence ministry -- next to the Ho Chi Minh City airport that, local residents say, should be used to develop the airport itself.

"Is it built to serve tycoons and corrupt officials? No civilians can afford to play golf," resident Huynh Dang said, according to a report in the official Thanh Nien newspaper.

The military also ran into controversy over plans -- since abandoned -- to evict a bear sanctuary in order to develop defence ministry land near Hanoi.

The army has companies that earn hundreds of millions of dollars a year, supplementing the defence budget, said Professor Carl Thayer of the University of New South Wales in Australia.

And as these companies also employ veterans and military families they are a powerful lobby group, he added.

Even as the army's business interests grew, its size has shrunk, from roughly 1.2 million men in uniform at the end of the 1980s to under 600,000 now, although Thayer said they still have some five million reservists.

In the face of its vast northern neighbour China, Vietnam's military finds itself back in the same position it once was with the French at Dien Bien Phu -- playing David against Goliath.

"Goliath is out there building shields and bigger ships and the Vietnamese have got a lot of good slingshots," Thayer said.