Anthropic wants tests, not bans, as OpenAI and Google back open weights

Anthropic does not want open-weight AI models banned. CEO Dario Amodei said so plainly today after a week of criticism. Instead, he proposes mandatory safety testing for every sufficiently capable model before release. The catch is that nobody has defined where “sufficiently capable” begins, and that determines whether tomorrow’s next open-weight models stay available.

“Anthropic has never advocated for a ban on open-weight models,” Amodei writes in this letter, calling models without dangerous capabilities “a public good” that cost nothing beyond the compute to run them.

His proposal has three parts: tighten export controls on advanced chips and chipmaking equipment, crack down on industrial-scale model distillation, and require safety evaluations for every sufficiently capable model before release.

The first two are aimed at Washington. The third would affect developers preparing models for release.

Amodei calls the testing idea close to consensus, noting the Trump administration has moved that way and that recent industry proposals would apply testing regardless of a model’s origin or license, “while exempting less capable models, such as those from startups and academia, entirely.” The exemption is critical, though; again, the term startup can be hard to pinpoint. Once some models are exempt and others are not, the policy becomes a capability threshold by another name.

So where does the line fall? Nobody has said.

The letter does not name who would set the number or who would run the tests. Model capability could be measured by metrics like benchmark results, training compute, or scores evaluated against defined risk categories. And the chosen metric would dictate the model type. Whoever picks the metric is also setting release timing for every lab that publishes weights.

This is a fast-moving story. The “Open Weights and American AI Leadership” letter so far counts 50 signatories, with OpenAI and Google joining Microsoft, Nvidia, Meta, AMD, Cisco,…