Among the cactuses in the desert of Arizona, just outside Phoenix, an extraordinary collection of buildings is emerging that will shape the future of the global economy and the world.

It is, in my view, the most important factory in the world, and it’s being built by a company you may not have heard of: TSMC, Taiwan Semiconductor Manufacturing Company. It makes 90% of the world’s advanced semiconductors. Until now they were all made on the island of Taiwan, which is 100 miles east of the Chinese mainland. The Apple chip in your iPhone, the Nvidia chips powering your ChatGPT queries, the chips in your laptop or computer network, all are made by TSMC.

They’re hugely protective of the secrets that lie within. Important customers, such as Apple and Nvidia, trust this company to safeguard their designs for future products.

But after months of asking, TSMC let the BBC in to look at the partial transfer of what some argue is the most critical, expensive, complex and important manufacturing in the world.