Tsao said he had been particularly disturbed by an incident at Yuen Long metro station when pro-China thugs ruthlessly beat passengers while the police appeared to delay their response.
Tsao, who was once reported to be worth £2.3 billion ($4.3b), had previously taken Singaporean citizenship, but last month said he had reinstated his Taiwanese passport.
"The people of Taiwan need a morale boost... so I gave up my Singaporean citizenship and came back here to be with everyone," he said, adding that he had decided to remain in Taiwan until his death.
"The first way [I could die] is an illness, which is beyond my control," Tsao said. "The second is dying laughing while watching the fall of the CCP [Chinese Communist Party]."
The CCP claims Taiwan as its own territory even though it has never ruled there, and has threatened to invade if the island does not agree to be annexed.
In recent months, Beijing has stepped up aggressive military drills around the democratic island nation, prompting urgent debate about how Taiwan can best defend itself, including whether it should create a more robust civil defence force.
Last month, Tsao offered to donate three billion Taiwanese dollars to bolster the island's defences.
Taiwan's Government has said it will evaluate whether his plans are feasible.
UMC distanced itself from its founder, emphasising that he had retired and now had "nothing to do with UMC".
