The US government has restricted the export of powerful AI models Fable and Mythos to anyone outside the US, citing national security concerns. This move has sparked a standoff between the government and AI giant Anthropic, which has pulled its models from the market. The episode raises questions about the effectiveness of export controls in containing frontier AI, a technology that has proven challenging to regulate in the past. Why it matters: This move highlights the ongoing debate about the balance between national security and technological innovation, and how governments will navigate the complex landscape of AI development and export.