US reverses course, restores UK access to frontier AI models for testing

The US government has walked back a directive that kept Britain from testing new AI models before their release. As of October 11, 2026, the UK’s AI Security Institute (AISI) once again has access to pre-release systems from Anthropic, Google DeepMind, and OpenAI. The pause lasted just 17 days. What happened, and how fast it unraveled On September 24, 2026, the Trump administration asked OpenAI and Anthropic to stop sharing new AI models with the UK’s AISI. The hold was meant to last until a comprehensive US national security review was finished. That was a sharp break from how things had worked. Under earlier voluntary arrangements, the UK received early access to emerging AI systems so its researchers could probe them before the public did. UK AI minister Kanishka Narayan lobbied to reverse the decision. On October 11, 2026, the US reversed its earlier directive, and the UK’s access was restored. The restored access covers three of the biggest names in the field: Anthropic, Google DeepMind, and OpenAI. Notably, Google DeepMind was not named in the original September request, which targeted OpenAI and Anthropic specifically. The Claude Mythos 5.1 wrinkle The pause had at least one...