Apple Inc. is finding itself squarely in the crosshairs of President Donald Trump’s new tariffs, even after a yearslong effort to insulate the iPhone maker from trade wars and supply chain disruptions.

A long list of levies unveiled by the White House are poised to hit the company especially hard, triggering an after-hours stock rout on Wednesday. The new reciprocal tariffs — a tax on imported goods in response to existing tariffs — will reach 34% for China. That would bring the total rate on Chinese goods to 54%, threatening to roil an Apple supply chain that still has the Asian country at its heart.