President Trump has imposed tariffs on all America’s trade; China has hit back; other nations, including our own, are working out how to cope with what Sir Keir Starmer has called a “new world” governed by “deals and alliances” rather than rules. In this crisis, we have turned to the economists, who argue about percentages. But shouldn't we be asking – what is the moral thing to do?

Trump’s ‘MAGA’ project always said it wanted tariff barriers to revive US industry and rebalance world trade; the American voters chose that strong medicine; now they – and the rest of the world – must swallow it. The first question is not whether it will work; time will tell. The first question is: given the consequences for the whole world, does Trump have a moral right to exercise that mandate?

The second question is the one that confronts Britain, and all the other nations that have been reliant (perhaps too reliant) on trade and co-operation with America. It is not about numbers but about morality. The three most influential economic philosophers in history – Adam Smith, Karl Marx and J.M.Keynes – reached different conclusions about it.

Is free trade a moral good?

Chair: Michael Buerk Producers: Peter Everett and Dan Tierney Editor: Tim Pemberton

Panel: Anne McElvoy Ash Sarkar Matthew Taylor James Orr

Witnesses: Mariana Mazzucato Hamish McRae Maxwell Marlow Sir Dieter Helm