Pentagon has barred contractors from working with Anthropic, and Microsoft will continue to provide customers access

Brief on the latest news:

What happened and how it has been reflected

The U.S. Department of Defense (Ministry of War) – “has moved to action”
This week it announced that Anthropic is now considered an unreliable AI supplier and stripped all contractors of the right to work with this startup.

Microsoft and its clients
Microsoft lawyers analyzed the laws and concluded: their own users can continue to use Anthropic models through proprietary software.

U.S. defense sector
Some companies have already ordered employees to abandon Anthropic solutions in favor of alternative AI platforms. Under the law they could do so up to six months, but for government officials the refusal must be immediate.

Microsoft’s position
1) Defense Department employees cannot use Anthropic products via integration with Microsoft solutions (including Claude chat‑bot).
2) If a Microsoft client’s work is not related to defense, they are free to use Anthropic in Microsoft 365, GitHub and AI Foundry.

How it works in practice
- Integration from last fall

Microsoft has already been implementing Anthropic solutions into its services while not severing ties with OpenAI – an investor that has long held significant capital in the company.

- GitHub Copilot AI

Developers can use Claude through GitHub Copilot AI, and also have access to Codex from OpenAI. This allows them to switch between platforms at will.

- Microsoft 365 Copilot (since October)

Microsoft 365 clients have been able since early October to choose between Anthropic and OpenAI solutions within Copilot without restrictions if their activities are not defense‑related.

Conclusion: The U.S. Department of Defense has removed Anthropic from the list of reliable AI suppliers, but Microsoft continues to provide its clients with access to these models through its own services, provided it is not related to military tasks. Meanwhile, ministry employees must abandon the use of Anthropic products immediately.