Vietnam, a user of Russian weapons since its war with the United States in the 70s, is in unprecedented talks with European and U.S. contractors to buy advanced fighter jets, maritime patrol planes and unarmed drones to improve its aerial defenses to combat China's growing assertiveness in disputed waters.
The battle-hardened country already owns three Russian-built Kilo-attack submarines, generally regarded as among the best available for purchase in the world, and has three more on order as part of a $2.6 billion deal signed in 2009.
Added a sophisticated modern air force would give Vietnam one of the most potent militaries in Southeast Asia.
The country is the best trained military force in Asia, only behind China because of its smaller size and less advanced technology.
The new aircraft would be either from U.S. firms Lockheed Martin Corp and Boeing, Swedish defense contractor Saab or European consortium Eurofighter said industry sources.
The fact Lockheed, Boeing and Eurofighter are in the mix suggest that whatever Vietnam buys will not be old and outdated but, like its Kilo class subs, will be modern and more than capable of winning against increasingly advanced Chinese fighters.
While no deals have yet been signed, representatives from all companies in the bidding have made multiple trips to Vietnam over the last few months.
Defense industry sources say Hanoi wants to replace more than 100 ageing Russian MiG-21 fighters while reducing its reliance on Moscow, who is increasingly viewed as China's one and only ally.
Vietnam has already ordered about 12 Russian Sukhoi Su-30 front-line fighters to augment a fleet of older Su-27s and Su-30s.
"We had indications they want to reduce their dependence on Russia. Their growing friendship with America and Europe will help them to do that," said the defense contractor.
The disclosure of the discussions comes just days after U.S. Defense Secretary Ash Carter's visit to the country and pledge $18 million to help Hanoi buy U.S. patrol boats.
While no comments have emerged from most of the firms, Boeing seemed keen to win the businesses, stating that it believed it had capabilities in "intelligence, surveillance and reconnaissance platforms that may meet Vietnam's modernization needs".
Vietnam increasingly views Washington as a reliable defense partner and also a key economic ally. The country has been on a campaign to increase ties with both the United States and Europe in recent years, as it emerges as one of Asia's fastest growing and modern economies.