In September this year a retired tech billionaire in Taipei, white-haired and bespectacled, called the island's media to a press conference to tell them he was pledging one billion Taiwan dollars (£28m; $32m) to create a civilian army.

Dressed in a bulletproof vest over a business shirt, Robert Tsao declared he wanted to help his countrymen and women fight against China.

The aim was to train up three million civilian "warriors" - a seventh of the population - in three years. Office workers, students, shopkeepers, parents could all learn to pick up a gun; he wanted 300,000 sharpshooters.

The task was ambitious, he acknowledged. But he vowed it could be done.

He brandished a picture of a fresh Taiwan identity card, something he'd re-applied for after renouncing his Singapore passport. He wasn't running away, he said. And he wasn't scared.

"I think as long as people are in Taiwan, they will be willing to defend their country. They are not afraid of Chinese military aggression," he told the BBC a few weeks later.

Born in China but raised in Taiwan, Mr Tsao created the United Microelectronics Corp semiconductor company, making his fortune in an industry the island is now globally known for.

As a businessman, he had many dealings in China. An ardent student of history, he has been a high-profile voice in policy debates for decades. In 2007 he championed the idea of a referendum on unification with the mainland.

But he is now among an increasing number of Taiwanese who feel they need to prepare for a possible invasion.

Xi Jinping is set to enter a third term as Chinese Communist Party (CCP) leader - something that has not happened since the rule of the first Communist-era leader Mao Zedong. Achieving what Mr Xi calls "reunification" with Taiwan would seal his legacy.

His decade in charge has seen huge modernisation and expansion of China's military capability. The People's Liberation Army (PLA) has increased activity around the Taiwan Strait, the 160km (100 miles) body of water between the island and the mainland.

Such activity has barely stirred the Taiwanese public, accustomed over decades to Chinese sabre-rattling.

But Beijing's crackdown on Hong Kong in 2019 shattered some of that complacency. Pro-China voices had long held Hong Kong up as an example of what Taiwan could be if it united with China - another example of "one country, two systems" where democracy could be retained.

This year has been another wake-up call, says Mr Tsao. Russia's invasion of Ukraine reverberated in Taiwan.