Open this photo in gallery: Almost all of Apple's manufacturing is done in whole or part by outsourced partners in Asia – the region of the world hit hardest by Mr. Trump’s tariffs.Gene J. Puskar/The Associated Press Apple Inc. APPL-Q became the world’s most valuable company in part by leveraging global supply chains to make its best-selling consumer technology products. In its most recent annual report, the company also flagged this global reach as one of its biggest risks. Now, tariffs imposed by the administration of U.S. President Donald Trump have indeed turned that strength into a key vulnerability. On...