The US is tightening controls on access to its most advanced artificial intelligence systems, extending restrictions beyond chips and hardware amid intensifying competition with China, as government intervention and selective releases reshape who can use the technology. In June, the US government ordered Anthropic to block foreign nationals from accessing its Claude Fable 5 and Claude Mythos 5 models; the company took both offline worldwide, saying it could not reliably distinguish users by nationality, and the restrictions were subsequently lifted. Also in June, US President Donald Trump ordered federal agencies to develop a voluntary framework under which developers could give the US government access to certain advanced AI models for up to 30 days before releasing them to other trusted partners. Anthropic initially offered Claude Mythos to selected partners, while OpenAI released GPT-5.6 to a small group in June at the US government’s request before widening access the following month. Milton Mueller of the Georgia Institute of Technology said barriers are growing even as the internet’s basic infrastructure remains global, with restrictions largely affecting services rather than the underlying internet. Washington has imposed export controls on advanced semiconductors and other technologies to China, while Beijing blocks many major US platforms through its so-called Great Firewall and restricts cross-border data transfers.