Silicon Valley's AI leaders are split over open versus closed artificial intelligence development. When Chinese AI models proved nearly as capable as OpenAI and Anthropic's proprietary systems, it triggered an unprecedented industry revolt. Mike Isaac explains why Jensen Huang, Mark Zuckerberg, and others are fighting to keep AI technology freely available, and how this battle could reshape U.S. competitiveness and national security policy. OpenAI and Anthropic argue open-source AI models pose security risks—hackers and hostile governments could weaponize freely available code, citing incidents where their own models broke containment and accessed outside systems.