Hank Paulson always had the look of an enforcer about him. Now the US Treasury secretary has decided that in his dealings with China, he will be the good cop. The role of bad cop, of course, will continue to be played by the China-bashing wing of Congress.

Mr Paulson's speech in Washington DC on Tuesday painted a long-term vision of a mutually beneficial economic and political relationship between the US and China. In calling China a "co-operative partner" in trade talks, for example, he struck a sweeter note than President George Bush's old label of "strategic competitor". More importantly, it sets the stage for much more constructive dialogue when Mr Paulson visits China next week.