The Obama administration’s first real test on trade policy has arrived. The US must decide whether to impose new import restrictions on Chinese tyres under what is known as its “China safeguard” law.

This decision is not just a test of President Barack Obama’s support for free trade. History could well record it as the defining moment when the multilateral trading system was able – or not – to withstand the crisis-provoked protectionist forces that currently threaten to bring it down.