Early Tuesday morning, the Financial Times published an interview with President Trump’s top trade adviser, Peter Navarro. The interview touched on a range of subjects — actually, one comment about the value of the euro has already caused the dollar to plummet — but one particular quote will send a shiver up Tim Cook’s spine.

“Mr Navarro said one of the administration’s trade priorities was unwinding and repatriating the international supply chains on which many US multinational companies rely, taking aim at one of the pillars of the modern global economy.

‘It does the American economy no long-term good to only keep the big box factories where we are now assembling ‘American’ products that are composed primarily of foreign components,’ he said. “We need to manufacture those components in a robust domestic supply chain that will spur job and wage growth.”

The implications here are huge. Using the example of Apple — although this will obviously affect far more than just iPhones — it’s a real departure from the kind of ‘Made in the USA’ that’s been talked about before.

Previous theories on what Trump would mean for electronics manufacturing imagined final assembly happening in the US only. The iPhone is assembled using components from a variety of factories, all centered in Asia. OLED screens, logic boards, fingerprint sensors and camera modules all make their way to Shenzen, where Apple’s manufacturing partner Foxconn turns them into iPhones.

Bringing final assembly to the US would be difficult, but plausible. Although America is lacking the vast supply of skilled manufacturing labor that makes iPhone manufacturing run smoothly, advanced robotics technology could probably remove that gap, which would make a US assembly plant plausible.

But moving the entire supply chain for the iPhone to the USA is implausibly difficult. Even for established companies in Asia, ramping up supply of a new component takes years, and isn’t always a perfect process. Suppliers started preparing to deliver OLED screens to Apple last year for a product that will ship in 2018, for example.

That two-year lead time gives some idea of how long it would take to wind up manufacturing in the US, even if Trump were to incentivize the process with tax breaks for US factories, and tariffs on imported goods. If it takes two years to build capacity for a new project in China and Korea, where skilled labor is already available and a supply chain already exists for necessary tooling, imagine how long it would take to start from scratch.

Trump’s trade plan is clearly focused on reducing the trade deficit. The logic goes that by reducing the trade deficit — or even turning to a surplus — jobs will magically appear in the US. More likely are increased prices, reduced consumer demand, and a general economic slowdown that won’t be making anything great again.

Chris Mills has loved tinkering with technology ever since he worked out how to defeat the parental controls on his parents' internet. He's blogged his way through Apple events and SpaceX launches ever since, and still keeps a bizarre fondness for the Palm Pre.