Twenty-four years ago, Wang Yu-chi, a law school junior at National Taiwan University and member of the school's debating team, heatedly argued with opponents from Nanjing University on whether "peaceful coexistence of mankind is a possible ideal".

"We need to pursue survival, be realistic and have our feet planted firmly on the ground," he said on the "con" side in the final of a 1990 Asian varsities debate in Singapore. In the end, his team won.

But on Wednesday, Wang - now Taiwan's mainland affairs chief - was telling a different story to Nanjing University students.