Opinion | The Dangerous A.I. Nonsense That Trump and Biden Fell For

China’s tech industry recently gave the U.S. tech industry — and along with it, the stock market — a rude shock when a start-up called DeepSeek unveiled an artificial intelligence model that performs on par with America’s best but that may have been developed at a small fraction of the cost and despite trade restrictions on A.I. chips.

Since then there have been a lot of frantic attempts to figure out how DeepSeek did it and whether it was all above board. Those are not the most…