An Unending Trade War Leaves Wall Street Jittery

Investors are dealing with a painful new reality: The trade war between the United States and China could last indefinitely.

That anxiety spread across the stock markets on Monday, as investors around the world tried to divine the potential fallout to economic growth and corporate profits. Bonds and commodities, too, flashed warnings of a slowdown.

The stock losses have brought an end to a recent calm that had settled over Wall Street. For months, investors had assumed that the trade war, a major hazard for the global economy, would end...