Hello, I’m the FT’s US trade correspondent Aime Williams, filling in for Alan Beattie while he’s on holiday. In today’s newsletter, I’m aiming to give a bit of a dispatch from the US capital, where President Donald Trump’s trade war is riven with new tensions between his diplomatic, economic and political goals.

Charted Waters, where we use data to analyse world trade, is on China’s export engine, which shows no sign of letting up. Email me at aime.williams@ft.com.

It’s a funny moment for Trump’s trade war. Gone are the heady days when hastily composed rage-tweets threatening huge tariffs on US allies were splashed across the front pages. Now those threats are made less often and mostly draw resigned shrugs.

Trump’s lost ability to use “emergency” tariff powers is one part of that after the US Supreme Court constrained him back in February. Another is the mood in America right now. The administration is staggering towards the midterms still embroiled in a costly war with Iran that has pushed up oil prices, driving inflation across the US economy and, perhaps most devastatingly, at petrol pumps. The combination of those two factors has changed Washington’s approach. 

In recent months, Trump’s advisers have been warning him against doing anything that could risk the shocks of his early trade war days, when his steep tariffs triggered a global stock market rout and a sharp sell-off in US Treasuries.

Since then, we’ve seen a lot of exemptions, carve-outs and general tinkering. We’ve also seen a few “national security” probes which, despite being expected to lead to duties, have concluded only with recommendations of further talks. The Section 232 investigations into critical minerals and aeroplane parts spring to mind.

Trump is not going to give up on tariffs. And he still hasn’t forgiven the Supreme Court for knocking down his original wall: he posted on his Truth Social platform railing against the justices for costing the US “TRILLIONS AND TRILLIONS OF DOLLARS” just a few weeks ago. (The reality is that one dogged judge in the lower Court of International Trade has hounded customs officials into refunding more than $100bn of those duties to date.)

But it’s fair to say the trade war has passed into the hands of the professionals. Now reliant on a patchwork of obscure laws, US officials have set up a series of new investigations and probes that could all lead to tariffs.

These have started bearing fruit. The US hit 60 trading partners with tariff rates ranging from 10 per cent to 12.5 per cent after a probe into “forced labour”, carried out under Section 301 of the Trade Act of 1974, just as previous global levies of 10 per cent — imposed under Section 122 of the same act — expired.

Moreover, officials launched a separate investigation — also carried out under Section 301 — into excess manufacturing capacity. This probe includes the EU, China, Singapore, Switzerland, Norway, Indonesia, Malaysia, Cambodia, Thailand, South Korea, Vietnam, Taiwan, Bangladesh, Mexico, Japan and India.

But what of the previous trade deals Trump struck with partners that promised them specific tariff rates? Behind the scenes, US trade officials are telling many allies that their deals will stand. But a new wave of tariff probes has left diplomats concerned that the agreements will be overwritten by combinations of new levies.

Take the EU. Including the most-favoured nation rate, the bloc now faces an extra US tariff of 10 per cent as a result of the recent “forced labour” probe. But under the bloc’s 2025 trade deal struck in Turnberry, it was handed a 15 per cent duty on most goods. That means if the forthcoming probe into structural overcapacity concludes with a tariff on EU goods of more than 5 per cent, Turnberry gets broken. Many diplomats fret the rate will come in higher.

One thing the Trump administration could do if it wanted to both wield big threats and keep its word on previous deals is diligently complete its investigations and recommend large duties for US trading partners but suspend their implementation pending further negotiation.

Dan Mullaney, a former US trade negotiator, pointed out that in 2018, the first Trump administration threatened tariffs under Section 301 in retaliation for EU digital services taxes, but suspended applying them to allow international talks to take place at the OECD.

Taking this approach would be one way to increase the urgency of talks with some of the US’s partners that are dragging on. India, for example, is continuing to be slow and hard work for US negotiators trying to push forward on progressing a trade deal.

The US has also been sending nasty letters to the EU reminding Brussels of White House demands and complaints about non-tariff barriers. Trump’s US trade representative, Jamieson Greer, has been vocal about the bloc’s slow pace of implementing both tariff cuts and rollbacks of rules and regulations. 

Most recently, EU fines on US tech companies such as Apple, Amazon and Meta have caught Trump’s eye, triggering the threat of more tariffs. These, too, would need to be imposed following an investigation, which Trump officials have previously threatened to start.

It’s worth making a bit of an aside here about Canada, which seems to be the subject of a new experiment by Washington to test out a novel use of Section 338 of the Tariff Act of 1930, an authority that has never before been used to impose duties on a trading partner. Specifically, US officials are trying to hit their northern neighbour with duties on about $20bn worth of goods to retaliate for unfair treatment on American cars, alcohol and cheese.

As ever, though, these duties are suspended for a while to allow the painful trade talks between Trump and Canadian Prime Minister Mark Carney’s team to bear fruit. It’ll be worth watching whether those tariffs actually bite, which they’re set to do in less than a fortnight.

Broadly, the mechanisms for ratcheting up pressure on US trading partners again are certainly there, even as Trump’s advisers fret about the US economy in the run-up to the midterms. For now, Washington is keeping its options open.

Despite Trump’s best attempts, China’s trade engine remains robust, with the country’s exports rising by almost a quarter last month on a year earlier.

• Both Trump and young Americans are warming to China, suggests Ali Wyne, senior research and advocacy adviser for US-China relations at think-tank International Crisis Group.

• China plans to bypass shipping chokepoints with an “Ice Silk Road”, a route through the Arctic that will skirt the north Russian coast on its journey between Ningbo and Felixstowe, UK.

• Joshua Kurlantzick of the Council on Foreign Relations think-tank points out that, while leaders at a recent Asean foreign ministers meeting were angry at the US, they did almost nothing about it.

Trade Secrets is edited by Harvey Nriapia