Protectionism is dangerous and a trade war would be extremely bad, former United States President George W. Bush said in Shanghai yesterday.

He said he was concerned about protectionism and the Great Depression experiences had already showed its ill effects.

Bush said China was an important country on the world stage and it was important to build good relations with it. He had done so by having regular meetings with state leaders during his presidency.

"I spent a lot of time trying to get to know them man to man and to understand how they think and their concerns," he told the 2010 Halter Financial Summit yesterday in Shanghai.

The US started with the strategic economic dialogue to make sure US and Chinese officials were able to have a good relationship and a good understanding, he said.

The theme of the summit - "China in a Changing World" - was to explore how China had managed to thrive when the rest of the world was struggling in the recent recession and what role it would be playing in the global economy in the future.