The global economy has been thrown into uncharted waters

What he did took the global economy into uncharted waters with no ideas about what lies there.

What is certain is that the damage will be massive for stability, trade and economic growth; American consumers will be among those paying a heavy price for his decision.

Far from being a liberation day, to use his description, it will be remembered as the day a US president took the worst economic decision in history. Much has been said about the decision for various sectors but agriculture will not be immune.

American farmers are already losing markets because of punitive tariffs imposed by China before the latest increase in tariffs. European farmers will lose out because, after China and the UK, the United States is a massive market for the European food industry. Below these top line consequences there are others.

Products that lose traditional markets will go elsewhere and that will cause unexpected damage far beyond the rest of the world versus the US dispute Trump has triggered. It seemed bizarre that in the adoring audience put together to bolster Trump there were farmers.

Their exports will be damaged and this may help Thump use a US food surplus to drive down prices for consumers. This was one of his election pledges and the farmers in the White House Rose Garden audience cheering him on could be picking up the bill. Credit has to go to the farming lobby here for its speed in getting out the message that trade concessions to the US pose a risk to farming across the UK.

In his White House speech accusing countries around the world of all sorts of sins against the US, Trump singled out non-tariff barriers to trade. These refer to rules around differing standards, so-called phytosanitary barriers to trade.

Trump specifically mentioned countries, including the EU and UK, that keep out American beef, some GM products and poultry.

With beef the US spat is over the rejection of beef treated with hormone growth promoters and poultry where chlorine washing is an alternative to higher production and processing standards.

The farming lobby fears are that UK opposition to these will be diluted to secure a trade deal. This would hit UK farmers, while at the same time damaging the close to free trade relationship we have, despite Brexit, with the EU as our biggest and most profitable market. The UK government wants to cobble together a trade deal with the US, seeing a 10 per cent tariff rate against 20 per cent for the EU as a good starting point. It knows there are big problems with this.

First and foremost Trump is a bully not to be trusted. In any negotiation his word is definitely not his bond. He loves to divide and rule and he wants to separate the UK from any allegiance or alliance with the EU he hates.

This is not in the UK’s interests. Keir Starmer might put a brave face on it, but he cannot feel any political allegiance for Trump. Some Brexit supporters are claiming it saved the UK from higher tariffs, but that argument holds no economic water, not least for the UK’s biggest export sector to the US, which is the car industry. The danger for agriculture comes on many fronts. One is the direct damage to exports to the US. Then comes how the shape of global trade in food will change as businesses rush to find new markets while exploiting the US being squeezed out of huge markets, not least China. That will deliver changes both good and bad, but impossible to forecast. There is also a risk if the UK does not go along with European sanctions against the US. This would threaten relations with our natural allies and biggest market to side with a maverick US president not to be trusted. Above all there is the threat of the US exploiting the desperation of the UK government for a speedy trade deal with Washington. It will want concessions on market access, not least for food that does not meet UK standards. It would be then that the alarm bells rung by the farming lobby reach a crescendo and the fears come to pass about the dangers of a rushed trade deal by a government with no interest or vision for agriculture.