The Senate’s rejection of Pre-sident Woodrow Wilson’s commitment that the US would join the League Of Nations was the greatest setback to American global leadership of the last century. While not remotely as consequential, the House votes last week that, unless revisited, would doom the Trans-Pacific Partnership, send a similarly negative signal regarding US willingness to take responsibility at a critical time for the global system.

Repudiation of the TPP by Congress would neuter the presidency for the next 19 months. It would reinforce concerns that the vicissitudes of domestic politics are rendering the US a less reliable ally. Coming on top of US failure to stop or join the Asian Infrastructure Investment Bank, it would signal a lack of US commitment to Asia at a time when China is flexing its muscles. And it would strengthen companies overseas at the expense of US businesses.

Both the House and Senate have delivered majorities for the trade promotion authority necessary to complete TPP. The problem is with the complem-ent-ary trade adjustment assistance programme, designed to assist American workers, which most Republicans do not support and Democrats are opposing in order to bring down the TPP. It is to be fervently hoped that a way through will be found to avoid a catastrophe for US economic leadership.