The Anthropic CEO has hit back at claims his company wants Chinese open-weight models banned, days after sitting out a rival industry letter.

Anthropic CEO Dario Amodei has moved to quash what he called a specific accusation circulating in AI circles this week, that his company wants Chinese open-weight models banned in the US as a way of protecting its own business.

In a post titled ‘Our position on open-weights models’ on the Anthropic website yesterday (27 July), Amodei wrote that “Anthropic has never advocated for a ban on open-weights models”, and said open-weight models without dangerous capabilities are a public good that cost nothing beyond the compute needed to run them.

The post follows an open letter published on 24 July and hosted on Nvidia’s website, titled ‘Open Weights and American AI Leadership‘, which urged US policymakers not to impose broad restrictions on open-weight models. The letter was signed by virtually all the big tech players including Nvidia, Microsoft, Meta and Hugging Face, and later grew to include OpenAI and Google – signatories stand at 50 today. Anthropic did not sign.

The letter emerged amid reports that US officials were weighing restrictions on the use of Chinese open-weight models by American businesses, first reported by Axios on 21 July.

Amodei set out two concerns he said protectionist bans would not address. The first is that authoritarian governments, not only the Chinese Communist Party, could build more powerful AI models than the US and use them for military advantage or domestic repression. He noted this is a concern whether or not such models carry open weights.

His second concern is that powerful models, open or closed and regardless of country of origin, could be misused for cyberattacks or biological attacks. He argues open-weight models carry extra risk here because guardrails are hard to apply once weights are released, and released weights cannot be withdrawn.

That said, Amodei says banning US businesses from using such models would not stop bad actors, who are unlikely to be legitimate US companies in the first place.

In place of a ban, Amodei said Anthropic continues to support three measures: blocking the sale of powerful chips and chipmaking equipment to China and cracking down on smuggling; targeting industrial-scale distillation operations that let Chinese labs narrow the gap to the US frontier without matching compute; and mandatory safety testing, covering cyber, biological and alignment risks, for all sufficiently capable models regardless of whether they are open or closed, or where they were built.

He said he agreed with parts of the industry letter, including that open weights expand access to the AI economy and strengthen competition, but disputed its suggestion that broad access necessarily helps defenders more than attackers.

He pointed to biological risk as an example, arguing that a sufficiently capable model could help weaponise a pandemic-level virus quickly, while building a defence against such an attack is a multi-year undertaking even in the best case.

Amodei said questions about whether open models carry extra risk, and whether that risk can be mitigated, should be settled through pre-release testing rather than assumed in advance.

Don’t miss out on the knowledge you need to succeed. Sign up for the Daily Brief, Silicon Republic’s digest of need-to-know sci-tech news.