By Laurie Chen, Michael Martina BEIJING/WASHINGTON (Reuters) -When the leaders of some of the world's largest companies flocked to Beijing for a business forum last month, their main purpose was a coveted meeting with Chinese leader Xi Jinping.

President Donald Trump’s tariff onslaught has roiled Washington and Wall Street for nearly a month. If the trade war persists, the next upheaval will hit much closer to home.

Fears of pandemic-era shortages at American stores have made a big comeback as shipping-container traffic between China and the U.S. plunged in the wake of President Trump’s tariffs.