Anthropic's lonely island

Anthropic spent this winter and spring as the darling of America's AI boom, conquering the frontier while casting itself as the industry's moral conscience.By summer, the Claude maker had found itself alone on an island of its own principles.Why it matters: Anthropic is simultaneously the world's most valuable startup and its most isolated AI leader. The company's idiosyncrasies have strained its relationship with developers, policymakers and partners as it barrels toward a potential trillion-dollar IPO.Driving the news: Anthropic is the only frontier AI lab that declined to sign an open letter led by Nvidia CEO Jensen Huang urging Washington not to restrict open-weight models, a category currently dominated by China.Open-weight models are downloadable systems that users can run, modify and build on without paying for a company-controlled interface — making them cheaper and more flexible, but also harder to control once released.Google and OpenAI, Anthropic's two biggest closed-model rivals, joined dozens of other signatories over the weekend, leaving Anthropic alone in defending the business model all three companies still depend on. What they're saying: Anthropic CEO Dario Amodei tried to defuse the fight himself on Monday, publishing a blog post insisting Anthropic has never called for banning open models — while still not signing onto the letter.Amodei called less capable open models "a public good" and said banning U.S.

companies from using Chinese open models would do little to stop hostile governments or bad actors.But he doubled down on the need for tighter controls on the ingredients and behaviors that could make powerful models dangerous, including advanced chips flowing to authoritarian governments.Between the lines: The open-weight controversy captures the new bad blood roiling Silicon Valley, where style and posture matter just as much as policy.Anthropic is more willing than its chief competitor, OpenAI, to be openly confrontational, even when the two companies are not always that far apart intellectually or commercially.Zoom out: As the AI race accelerates, the company is growing isolated across nearly every major policy fight:🪖 Military use: The Pentagon blacklisted Anthropic in February after a bitter fight over whether Claude could be used for mass surveillance or autonomous weapons. Top Pentagon official Emil Michael lashed out at Anthrop…