Wanted: a credible mediator to bring a global trade war to armistice. Must have: the trust of the aggressors, the law on its side and the clout to get things done.

The US, for years the dominant power in the world trading system, and its upstart Chinese challenger are at battle stations. The other big trading economies, particularly the EU and Japan, are trying to talk them down from a full-on conflict in which their own economies are already suffering collateral damage. But nothing has so far deterred President Donald Trump from unilaterally hitting more than $200bn of imports from China with emergency tariffs and threatening more.

If the need is clear then so is the obvious vehicle for de-escalating the conflict — the World Trade Organization. In principle it could resolve the antagonism between Washington and Beijing through providing the forum for litigation and negotiation. But its weaknesses make it an awkward arbiter. At the time the WTO is most needed, its failings become ever more manifest. Without reform, the organisation itself will suffer severe, possibly fatal, collateral damage from the US-China struggle.