Well, well, well.

In a US customs messaging note quietly slipped out in the early hours of Saturday, a series of numbers were listed as exempt from the 125% tariff on goods entering the country from China.

The code "8517.13.00.00" means very little to most of the world, but in the US customs list it represents smartphones.

The inclusion meant the number one Chinese export to America by value last year was exempted from the import taxes, alongside other electronic devices and components, including semiconductors, solar cells and memory cards.

In the context of the US Commerce Secretary Howard Lutnick just days ago announcing that part of the point of escalating tariffs on China was to bring back iPhone production to the US, this was a stunning about-turn.

The US has now excluded the single biggest Chinese export, and certainly the most high-profile finished good from tariffs, without publicly announcing it at first.

It is worth considering what would have happened in the absence of this exemption.

The effect of 125% tariffs on Apple's Zhengzhou manufacturing facility in eastern China would have started to show in weeks at most American Apple stores. It would have been a totemic "sticker shock" for the White House's tumultuous tariff push.

According to Counterpoint, a global technology market research firm, as much as 80% of Apple's iPhones intended for US sale are made in China.

The tech giant's manufacturing profit margins are estimated to be between 40-60%. Typical iPhone prices might have moved closer to $2,000 (£1,528) than $1,000. The other option for Apple could have been to spread the cost across all of its global prices, but would the rest of the world accept paying a Trump tariff tax?

A very public repricing of iPhones has been avoided, but still may occur if, as the White House has said, the previously imposed 20% tariffs on China related to the powerful opioid fentanyl, remain in place.

Tim Cook, the chief executive of Apple, is a key player here. He can walk into a meeting with both US President Donald Trump and Chinese President Xi Jinping. It is not an outlandish prediction to suggest that, if it comes, any peace in the US-China trade war could be brokered by Mr Cook.

That's based on his deep fundamental role in connecting the two economies. He was hand-selected by Apple's co-founder Steve Jobs for his unrivalled expertise in just-in-time supply logistics.

'Art of the Repeal'

This is all moving rather quickly now. Weekend reports in the US press claim White House trade hawk Pete Navarro is being sidelined too, in favour of US Treasury Secretary Scott Bessent.

Navarro was the author of the infamous equation that set so-called reciprocal tariff rates in proportion to the size of a country's trade surplus with the US, calling it "the sum of all cheating".

Bessent is now leading negotiations with trade partners seeking to avoid the reapplication of those rates after the 90-day pause.

There is a big question after 10 days of chaos. What is the incentive for other nations to offer much here? The Trump administration is clearly spooked by the bond market reaction to the president's trade plans, and questions surrounding the safe haven status of US debt for investors.

In trying to stave off effective interest rates on bonds rising to 5%, the US needs deals more than just those in surplus countries.

Indeed this weekend's broad range of exemptions are in and of themselves an astonishing U-turn on the principle embodied in the notorious tariff chart held up by Trump in the Rose Garden.

Just under a quarter of China's total exports are now exempt from the 125% tariff, according to Capital Economics.

The consultancy suggests there are other big winners from the exemptions, with 64% of exports to the US from Taiwan, 44% from Malaysia, and just under 30% from both Vietnam and Thailand now also exempt.

The 10% universal tariff is now riddled with exemptions, and the biggest carve outs are for many nations with massive trade surpluses from electronics manufacturing.

The new tariff equation is to give an effective discount from the universal 10% (through exemptions) to those with the biggest surpluses. For example, Taiwan has a $74bn surplus with the US, and Vietnam a $124bn surplus.

This is the exact opposite of the infamous Navarro calculation from last week. In 10 days we've gone from the "looters and pillagers" will be hit the hardest, to (apart from China) those with big surpluses getting the biggest exemptions.

Meanwhile an ally such as the UK, which according to US figures has a $12bn deficit - i.e. the US sells more to the UK than the other way round, has a 25% tariff on cars, its biggest goods exports, with number two, medicines, in line for similar charges.

The White House has gone from clearly suggesting there would be no negotiation on the baseline 10% tariffs to offering exemptions to the very products causing the deficit the entire policy was supposed to solve.

This is a lot more than a "row back". Some have called it the "Art of the Repeal". The 4D chess has been replaced by someone playing one dimensional checkers, but unable to tell the difference between opposing pieces.

The US is now negotiating with the bond markets, and itself. The rest of the world will just see how this plays out now.