The Pentagon accessed OpenAI models through Microsoft Azure prior to the official lifting of OpenAI's military use ban in January 2024. This was possible under the existing Azure cloud services contract, which allowed the Pentagon to use GPT models without direct negotiation with OpenAI. Microsoft, which has invested $13 billion in OpenAI since 2019, confirmed that Azure OpenAI services were not subject to OpenAI's usage policies. This arrangement was in place even before OpenAI announced support for certain government defense projects in January 2024, formalizing the Pentagon's existing use of the technology.