TIMELINE — Anthropic's Pentagon blacklist upheld in US appeals court: How the conflict unfolded

(Updates dateline and headline, recasts paragraphs 1 to lead with US appeals court ruling, adds details in table) Sept 25 (Reuters) — A US appeals court on Friday upheld the Pentagon's decision to blacklist Anthropic from military contracts, affirming the AI lab's designation as a national security supply-chain risk and extending a months-long standoff over military access to its frontier models. The dispute began early this year when the US Defense Department pressed Anthropic to remove safety guardrails from Claude. The demand escalated into a broader confrontation that led to the blacklist, lawsuits and bans by several federal agencies. Despite the ban, government agencies continued using Anthropic's tools as the White House and the company gradually mended ties ahead of Anthropic's planned IPO. Here is a timeline of the conflict: January 29 The Pentagon and Anthropic clash over eliminating safeguards that could allow the government to use its technology to target weapons autonomously and conduct US domestic surveillance February 23 US Defense Secretary Pete Hegseth summons Anthropic CEO Dario Amodei to the Pentagon for talks on the military use of Claude February 24 The Pentago