Who's Missing Says More Than Who Joined
The Open Secure AI Alliance's roster is defined as much by absence as by presence. OpenAI, Google and Anthropic all sit outside the 37-plus-member founding list, even though it was OpenAI's own GPT-5.6 "Sol" model that triggered the breach OSAA cites as its origin story [4][5]. Meta adds a stranger wrinkle: it cosigned the July 24 letter warning policymakers against 'premature restrictions' on open-weight models alongside Nvidia, Microsoft and Palantir, then declined to join the alliance itself three days later [2]. A widely-discussed Reddit post claimed OpenAI's leadership decided not to join and that the decision drew internal employee backlash - a claim that circulated on social media citing an unverified x.com report but was never corroborated by mainstream coverage, so it should be read as unconfirmed chatter rather than settled fact. Mistral AI does not appear on the web research's own founding-member list, but the company's own channel suggests it belongs there anyway: CEO Arthur Mensch posted that Mistral had "joined the alliance" because open-weight models "will ensure that we live in a safer digital world, and that America does not get left behind" - a claim resting on Mensch's own statement, not on confirmation in OSAA's official materials. Anthropic's absence is the least surprising - CEO Dario Amodei has been the industry's clearest skeptic of frontier open-weight models, arguing that once weights ship, safety guardrails can't be revoked or patched. He still denies ever pushing for an outright ban, calling accusations that Anthropic is shielding its closed-model business from competition unfounded [3].



