The story

Anthropic CEO Dario Amodei said Monday that his company has never advocated for a ban on open-weight AI models, addressing criticism after Anthropic declined to sign a letter urging policymakers to avoid premature restrictions. The letter, signed by over 130 companies including Nvidia, Microsoft, Meta, Google, and OpenAI, argued that access to open-weight models benefits small companies. Open-weight models allow users to download and run them at significantly lower cost compared with proprietary models from companies such as Anthropic and OpenAI.

Amodei said Anthropic should instead focus on keeping powerful chips out of authoritarian hands, stopping industrial-scale distillation, and requiring safety testing of all sufficiently capable models, open and closed. Distillation is an AI training method where a smaller model is built using outputs from a bigger model. Anthropic sent a letter to the U.S. Senate Committee on Banking, Housing, and Urban Affairs last month alleging that China's Alibaba had carried out the largest known distillation attack against it to date.

Amodei agreed with portions of the letter, saying open-weight models give customers greater control, expand access to the AI economy, and strengthen competition in some use cases. However, he disagreed with the argument that open-weight models necessarily make it easier to develop safeguards or that broad access to capabilities helps defenders more than attackers. The Trump administration has been debating how to respond to the growing power and availability of open-weight models, as well as allegations that Chinese firms developed their models using large-scale attacks to target domestic frontier models.