Trump aside, many imagine free trade is clearly the best economic strategy. Nations that opened their borders grew wealthy, those that closed stagnated. But the evidence tells a more complicated story. America became the wealthiest country in the world behind tariff walls that averaged over 40% during its industrial rise. The European Union — cheered on as a liberal success story — is seen as a highly protectionist bloc by emerging countries, with some dairy, meat, and sugar products having tariffs over 100%. Meanwhile, South Korea didn't build Hyundai and Samsung by trusting the market — the government backed handpicked industries, and blocked foreign competitors. China did the same.

Should we stop thinking of free trade as automatically a good thing and recognise that protectionism is sometimes essential for growth? Is free trade only effective when a country is economically dominant, as Britain was in the 19th century, and the US post WWII? Or has free trade been responsible in the last 70 years for the fastest rise in living standards the world has ever seen, which we abandon at great peril?

Former Chancellor Jeremy Hunt, heterodox economist Steve Keen, member of the FT editorial board Gillian Tett, and FT Chief Economics Commentator Martin Wolf debate free trade, tariffs, and dogma in economics.