The Department of Defense has issued internal guidance that allows, in narrowly defined cases, continued use of Anthropic’s artificial intelligence tools beyond an earlier six-month wind-down period if doing so is essential to national security missions.
The guidance is set out in a memo dated March 6 and signed by the Pentagon’s Chief Information Officer, Kirsten Davies. It states that exemptions may be authorized "in rare and extraordinary circumstances" and "will only be considered for mission-critical activities directly supporting national security operations where no viable alternative exists."
Under the terms of the memo, any Pentagon unit seeking such an exemption must submit a comprehensive risk mitigation plan for approval. The document instructs officials to make risk management a precondition for any approval of continued use.
The memo also directs officials to prioritize removing Anthropic’s products from systems that support critical missions, explicitly citing nuclear weapons and ballistic missile defense as areas where removal should be accelerated.
In addition to applying to internal Pentagon users, the memo reaffirms that the prohibition extends to defense contractors. Contracting officers have been given 30 days to notify contractors of the policy, and contractors must certify full compliance with the phase-out by the 180-day deadline.
The guidance was issued amid a contentious dispute inside the department over technology guardrails for use of Anthropic’s tools by the military. That debate reached its peak when the Defense Secretary labeled the company a supply chain risk and ordered a ban on the firm’s tools across the Pentagon and among its contractors.
Anthropic filed a lawsuit on Monday seeking to block implementation of the ban.
Legal and procurement experts say the narrow exemption carve-out underscores the practical difficulty of fully excising a vendor from complex technology supply chains. Franklin Turner, a government contracts lawyer at McCarter & English, described the memo as "a recognition of the fact that it’s really hard for most vendors to certify they have removed the company from the entirety of their supply chain."
Turner noted that contractors may struggle to ensure their software contains no open-source code originating from Anthropic, and added, "I do expect to see a flurry of waiver requests."
The Pentagon has confirmed the existence of the internal memo but declined to provide further comment. Anthropic did not immediately respond to a request for comment.
Context and next steps
The memo establishes a two-track approach: an overarching ban with narrowly tailored exceptions where no viable alternative exists and removal priorities for the most sensitive mission systems. It also places clear administrative deadlines on contracting officers and contractors to enforce the policy across the defense industrial base.