Elon Musk's AI company, xAI, has entered into an agreement with the U.S. Department of Defense to deploy its AI model, Grok, in classified systems. This development follows the breakdown of negotiations with Anthropic, whose Claude model was previously the only AI available for such use. Anthropic's refusal to relax security restrictions and allow the model's use for "all lawful purposes" led to the shift. xAI has agreed to these terms, prompting the Department of Defense to expedite talks with Google and OpenAI to ensure their models, Gemini and ChatGPT, meet the same criteria for classified deployment.