The June 15 filing was submitted in defense of gas turbines powering a large data center owned by Musk’s AI company xAI. The turbines are currently the subject of an environmental lawsuit.

In its argument, the US Department of Justice stated that the lawsuit “threatens American national, economic, and energy security by seeking to shut off the power supply for artificial intelligence innovation that supports the Department of War’s military operations.”

To support its position, federal prosecutors cited testimony from Pentagon AI chief Cameron Stanley, who said under oath that Grok is already being used in Project Maven, the US military’s AI-assisted targeting programme. The system was previously powered by Anthropic’s Claude model.

According to Stanley’s statement, the project’s Maven Smart Systems (MSS) “enabled US forces to deploy over 2,000 munitions to 2,000 distinct targets within 96 hours during Operation Epic Fury.”

He also praised Musk’s technology, referring to “the greatly increased operational efficiency made possible by the Grok Gov Model.”

Separately, the NAACP, a civil rights organisation, has filed a lawsuit against xAI, alleging that it operates multiple gas turbines without permits in violation of the Clean Air Act. The group claims the turbines contribute to pollution in predominantly Black neighbourhoods. xAI, however, maintains that the turbines are temporary and mobile and therefore not subject to regulation.

The filing also references broader changes in US defense technology partnerships. At the end of February, the government ended contracts with Anthropic after the company refused to allow its tools to be used for fully automated strikes or mass surveillance of Americans.

Following this, the Pentagon reportedly turned to other AI providers, including Google, OpenAI, and xAI, as part of its continued military AI development efforts.

Internal concerns over AI use in military operations have also emerged. At Google, more than 600 employees reportedly urged the company not to supply AI for classified military operations, citing ethical concerns.

The US military’s transition toward artificial intelligence continues to evolve. In March, the government acknowledged that Anthropic’s Claude model was still being used in operations related to Iran.

Musk, a close ally of President Donald Trump, merged xAI into his space exploration company SpaceX in February, which carried out the largest IPO in history on June 12.