A recent survey by the pollsters Opinium found that, whatever they may think of Donald Trump as a person, a majority of Britons actually like his policies. In most cases this makes sense. But his new-found enthusiasm for trade protectionism is worrying and, if I may say so, distinctly un-British.
Over the weekend, Trump announced a 25pc tax on most goods imported from Canada and Mexico, and an additional 10pc on goods from China. The president subsequently agreed to pause tariffs on Mexico for a month following last-ditch concessions offered by Mexican president Claudia Sheinbaum on Monday. But the threat remains.
The EU is surely next in the firing line, though it is hard to feel much sympathy. The EU has promoted free trade within its own borders. But in other respects, it is the world's biggest protectionist bloc, erecting barriers that make it harder for other countries - including the US - to sell into European markets.
The fallout from the new Trump tariffs has been immediate.
Equity markets have responded badly worldwide. Even US stocks have suffered from fears of a global trade war and worries that tariffs will prompt the Fed to keep US interest rates higher for longer. In turn, this has strengthened the US dollar and undermined the competitiveness of US companies, even before other countries retaliate against the US.
Oil prices have edged up too. Trump has recognised the importance of heavy oils imported from Canada and so imposed a lower tariff of 10pc on Canadian crude. But that is still high enough to have rattled energy markets, with US refiners already struggling with declining profit margins.
Trump has tried to sell tariffs as a tax paid by foreign companies. But in reality, they are paid by US importers and mostly passed on to consumers.
This is not just economic theory. Many studies have shown that most of the burden of the additional tariffs that Trump introduced in his first term was ultimately borne by US consumers. Moreover, the impact was typically felt most by poorer households.
Defenders of tariffs make two counter arguments.
One is that the replacement of imports with domestic production must be good for the economy and for local jobs.
Some US companies and workers will indeed be better off. But the economy as a whole will be worse off.
Free trade allows consumers to buy at the lowest price from the best producers and maximises choice and competition. Anything that acts again that is likely to be bad for productivity and growth in the longer term.
Frankly, it is depressing that this needs to be explained again to British readers. Have we really forgotten the lessons of the Corn Laws, or the writings of Adam Smith, David Ricardo and John Stuart Mill?
The other argument in favour of tariffs is that they should at least raise some additional revenue, allowing other taxes to be cut. However, the more effective the tariffs are in reducing imports, the less revenue they will raise. And the money they do raise will come mainly from lower income households, while damaging longer-term growth.
The UK economy should at least be less severely damaged than many others.
Assuming the UK itself is exempt from US tariffs and does not join in any retaliation by the EU (now made possible by Brexit), the net effect of a trade war on UK growth is likely to be small.
It is notable that the euro has fallen far more than the pound. But there could still be some significant impacts in both directions.
On the upside, UK consumers might benefit from the diversion of cheap Chinese goods to the UK market, while some UK companies may find their products are now more competitive in the US.
For example, British car manufacturers might benefit if the US imposes additional tariffs on vehicles made in the EU, provided they can show that enough of the parts and materials were sourced from the UK.
The UK will also be more attractive as a safe haven from the mounting problems in the EU and as a destination for inward investment.
However, the UK is already awash with cheap Chinese imports, and a further increase could fall foul of rules against "dumping". There is also relatively little overlap between what the UK sells to the US and what China does, meaning it will be difficult to substitute Chinese goods with British-made alternatives.
There are big risks to the UK economy on the downside, too.
US tariffs could tip both Canada and Mexico into recession. Moreover, assuming they are extended to the EU, tariffs could prolong the downturns in Germany, France and Italy too. In turn, this will undermine demand for UK exports and damage confidence further.
The other main threat to the UK economy from Trump's tariffs may be the spillover from higher US interest rates, rather than tariffs themselves. US and UK government bond yields are now moving in lockstep again. If the Fed is more reluctant to cut US rates, as seems likely, borrowing costs will also be higher for longer in the UK.
Admittedly, bond yields fell on Monday in the UK and in the rest of Europe. But this mainly reflected fears that the region's growth will be much weaker, so is hardly something to cheer.
Overall, then, the net effect of all of this on the UK economy is complex and uncertain. But in my view, and more importantly that of the market, it is more likely to be negative. Either way, it would be folly for Britain to copy the US and impose tariffs of our own.
Julian Jessop (@julianhjessop) is an independent economist