The US Treasury announced this weekend that it is postponing a report, which had been due later this month, on whether China is a currency manipulator. Not for the first time, this semi-annual ruling threatened to be a flashpoint in US- China relations. The administration of Barack Obama wants to maintain recent progress with Beijing on other issues and hopes, even now, for a friendly resolution of the quarrel over the renminbi.

The delay is wise. Long may it continue. Hu Jintao, China's president, has just announced he will attend a summit on nuclear security in Washington this month. The US continues to hope that Beijing will sign up to sanctions against Iran. Sacrificing agreements in these and other areas to make an empty gesture on the renminbi or, worse, to launch a series of escalating trade disputes, would be mad.

This is not to deny that China's currency policy hurts its trading partners. If US threats were likely to solve the problem, one might say: threaten away. Even discounting the need to get on with China on other issues, however, this is an unpromising approach. America must apply pressure more intelligently.