With Beijing growing in strength, a US scholar is calling for a major rethink on Taiwan in which the island would cut its troop numbers in half and rebrand its army as a self-defense force.

The proposal marks a rare break from the conventional view of American and Taiwanese policymakers that the island needs to close the military gap with Beijing, but its author said an opposite course could strengthen Taipei.

Scott Bates, president of the Washington-based Center for National Policy, said the balance was "irretrievably shifting" in China's favor and it was politically and economically unrealistic that Taiwan would commit enough to close the gap.

Instead, Taipei can take the lead by halving the size of its army, rebranding it as a Self-Defense Force in the style of Japan and renouncing any military action on mainland China's soil, he argued.

"If Taiwan were to take a bold step like this, that would change perceptions on the mainland and perhaps win some popular support for the Taiwanese position," said Bates, a former congressional aide.

"If there were a showdown, it might make (Beijing) think twice."

Taiwan should turn the new force into a disaster response team ready to deploy throughout Asia and also highlight the island's democracy through a major initiative that supports civil society across the continent, Bates said.

And instead of waging a battle to preserve a dwindling number of nations' recognition of Taipei instead of Beijing, Taiwan can use its diplomatic resources to seek solutions on Asia's bitter territorial disputes, he said.

The new Taiwanese approach would give the island the moral high ground, winning over global opinion and ensuring that China would appear to be the aggressor if it attacked, he argued.

"Mainland Chinese public opinion is beginning to matter more. The Chinese Communist Party cannot ignore its own people without repercussions," Bates said.

China considers Taiwan to be a territory awaiting reunification, by force if necessary. China's defeated nationalists fled to Taiwan after defeat by the communists in 1949, with the island developing into a self-ruling democracy.

The United States switched recognition from Taipei to Beijing in 1979 but at the same time Congress passed the Taiwan Relations Act, which requires Washington to provide the island with means to defend itself.

Bates said that his proposal would complement efforts by Taiwan President Ma Ying-jeou, who has sought to ease tensions with China by expanding economic ties, though domestic critics accuse Ma of jeopardizing the island's de facto independence.

Bates supported the continuation of the Taiwan Relations Act, saying the island needed a credible deterrent. While cutting its army, Bates called for Taiwan to launch a major upgrade of its air defenses and navy to show that any effort to gain supremacy over the island would be costly.

The Taiwan Relations Act enjoys virtually unanimous support in the US Congress, where lawmakers have pressed President Barack Obama to sell to the island new F-16 jets -- a step that China strongly opposes.

Bates' ideas, however, are unlikely to win quick support.

Joseph Bosco, a former Pentagon official, sharply criticized the proposal, saying it went against accepted concepts of deterrence and that Taiwan already had the moral high ground.

"Taiwan does not need to disarm unilaterally in order to prove its moral or political legitimacy," Bosco said Wednesday at an event where Bates presented his proposal.

Bates, who spoke last year at Taiwan's National Defense University and wrote an opinion piece in the Taipei Times, said he wanted to start a debate.

"It doesn't have to be my plan, but there does have to be a strategic rethink," he said.