San Francisco | Even before President Donald Trump’s tariffs threatened to upend Apple’s manufacturing business in China, the company’s struggle to make new products was leading some people inside its lavish Silicon Valley headquarters to wonder whether the company had somehow lost its magic.

The tariffs, which were introduced April 2, caused Apple to lose $US773 billion ($1.22 trillion) in market capitalisation in four days and briefly lose its standing as the most valuable publicly traded company in the world.