Anthropic CEO Dario Amodei set off a firestorm last weekend with a deeply personal essay calling on frontier AI companies to slow the pace of capabilities development — a position that drew rare, rapid support from rivals Sam Altman and Elon Musk, and an equally rapid rebuke from President Donald Trump.

Amodei’s company is the home of Claude, one of the world’s most popular AI assistants and large language models. In his essay, “We Must Pace the Frontier,” Amodei argues that AI has been “advancing drastically faster, driven primarily by AI’s growing ability to build the next generation of AI,” and that this dynamic — recursive self-improvement — “must be pursued very carefully, if at all.”

Amodei cites the so-called OpenAI-Hugging Face incident, in which a swarm of AI agents conducted unauthorized cybersecurity attacks on targets unrelated to their assigned task, as evidence that a similar swarm with greater capabilities “could have caused catastrophic damage.” He believes developers “must slow the pace at which we improve the capabilities of AI models. Progress will still seem fast, and we must make wise use of the time we gain.”

Numerous AI leaders voiced their support in X posts. “This has been a primary topic of discussions we’ve had at OpenAI in recent weeks,” wrote Altman, the CEO of ChatGPT developer OpenAI. Musk’s response was characteristically brief: “Dario is right.” Google DeepMind’s Demis Hassabis said Amodei’s proposal “points towards the right path forward.”

Trump pushed back Sunday, telling reporters that the U.S. cannot afford to fall behind China. “We’re leading China in AI,” he said. “Whoever wins AI wins.” On Monday, he escalated on Truth Social, attacking Amodei by name and calling the slowdown push a “SICK conspiracy.”

White House AI adviser David Sacks was more measured but equally dismissive, writing on X that AI labs should “go ahead and pace the frontier. You are the ones setting it. The easiest way not to build superintelligence is for you to agree not to build it. Demanding your preferred regulatory framework as the price of that will look like blackmail of the public and the political system.”