Anthropic’s September 2026 report details GTG-87001, a Yemen-based guided weapons engineering cell that used Claude Code to develop GNC software for three programs: a guided rocket, a multi-stage ballistic missile (>2,000 km range goal), and the R2000 set including a hypersonic glide vehicle variant.
The actors used parallel Claude instances with delegated roles — coder, researcher, reviewer — substituting for a human software engineering team. Safeguards blocked many requests; actors used evasion tactics including obfuscation and framing requests as academic research.
A live guided-rocket field test in Yemen appears to have failed. Anthropic found no evidence of an operational deployed weapon but confirmed AI coding agents moved beyond hypothetical questions into development-and-testing workflows. The group built an offline simulation toolkit that runs without Claude before accounts were banned.