Anthropic reports Yemeni militants attempted to use Claude AI for missile software

A weapons-engineering cell in northern Yemen spent roughly nine months using Anthropic’s Claude AI models to develop missile guidance, navigation, and control software, according to a report the AI company published on September 10, 2026. The cell, which Anthropic identified as likely connected to Iran-backed Houthi militants, ran projects from December 2025 through August 2026 before accounts were detected and banned. The group pursued three distinct weapons programs simultaneously: a guided rocket built around a phone-grade flight computer, a multi-stage ballistic missile designed for ranges exceeding 2,000 km, and the R2000 missile family, which included plans for a hypersonic glide vehicle. How the cell operated The Yemeni operatives ran multiple Claude instances in parallel, each assigned a different function. Some sessions handled coding tasks, others were dedicated to research, and a third category performed review of the outputs. Anthropic’s report, titled “Detecting and Countering Misuse of AI,” documented that the cell worked across several of Claude’s model tiers, including Haiku, Sonnet, and Opus. The cell apparently test-fired one of the guided rockets. It failed. Afte...