As it did last summer, the US Congress has just shown how its discord continues to erode America’s economic policy credibility.

Last year a fight over the federal debt ceiling placed the US recovery at entirely unnecessary risk. This year Congress has gone on recess leaving evidence of legislative dysfunction that, while less dramatic than that in 2011, underlines why the US is having such difficulty in projecting a coherent economic policy abroad as well as at home.

Lawmakers went home last week leaving two pieces of rather important business unfinished. First, the farm bill, which sets agricultural subsidies for the next five years, remains in limbo after the Republican House leadership saw it did not have the votes even to clinch a one-year extension of current law. Second, Congress failed to normalise trade relations with Russia. US businesses will be deprived of some of the benefits of Russia joining the World Trade Organisation, which it will do on August 22.