A Google DeepMind researcher has resigned over the company's work with the Defense Department, adding to the internal backlash over the tech giant's military partnership.
Alex Turner, a research scientist who worked for more than two years on AI safety at Google DeepMind, stepped down from his position in June, he told Business Insider. Turner said he made the decision after Google signed an agreement to let the Pentagon use its AI for classified operations.
The Pentagon confirmed in early May that it had signed the deal with Google and a group of other companies, including Microsoft, Amazon, and OpenAI, for "lawful operational use."
"When Google signed the deal, my conscience simply said 'nope,'" he told Business Insider.
In May, after the Pentagon announced its agreement with Google and other labs, a Google spokesperson said: "We remain committed to the private and public sector consensus that AI should not be used for domestic mass surveillance or autonomous weaponry without appropriate human oversight."
Google's Pentagon agreement has caused some backlash among its workforce. In April, around 600 of Google's nearly 195,000 employees signed a petition asking the company not to enter into any deal involving classified work. A classified agreement limits how much oversight Google has over how its AI is used.
One DeepMind researcher said on X that he was "ashamed" of Google's Pentagon agreement, while another employee published a resignation letter internally in May, also citing Google's closer relationship with the US military.
Turner said he started thinking about leaving Google in February, when he first thought Google would sign the Pentagon deal.
"I think I would have stayed a few more months if they hadn't signed the deal. When Google signed, I just couldn't do any more work. My brain said 'no,'" he wrote in a blog post published on Wednesday. He told Business Insider that he doesn't have another job lined up yet.
Turner said that earlier this year, he proposed a framework for military AI that he hoped Google might adopt, including provisions to ensure human control over AI targeting systems.
A Google spokesperson told Business Insider that the company had been receptive to hearing Turner's ideas.
Google's changing AI pledges
In early 2025, Google updated its AI principles to remove pledges that it would not pursue the use of AI for weapons or mass surveillance. Google DeepMind CEO Demis Hassabis co-authored a blog post at the time announcing the changes. The decision caused backlash from some employees at the time.
In an internal message to colleagues sent before he left, Turner said there was a disconnect between Hassabis' comments in an employee town hall that his principles hadn't changed and the decision to remove the pledges.
"If I can't trust this easily verifiable claim, how am I supposed to rest easy on the careful oversight he says protects us?" Turner wrote in the message, which was viewed by Business Insider.
Turner said he got the attention of executives at Google earlier this year.
He said he had lunch with Google's chief scientist, Jeff Dean, to discuss his concerns. He also helped organize an employee letter to Dean, who had publicly shown support for Anthropic during its spat with the White House over military use of AI. The letter called on Google to draw red lines in any agreements with the Pentagon, such as prohibiting Gemini from piloting autonomous weapons without human oversight.
Turner said he sent the proposal for his military AI framework to Hassabis earlier this year, and he told him to have it evaluated by two senior people working in policy at Google. After some discussions about next steps, Turner said he stopped receiving responses. Shortly after, the Department of Defense confirmed it had signed a deal.
"At that point, I couldn't stay at Google in good conscience, so I left," Turner wrote in his blog post.
Turner said he's working on independent AI safety and security work while he works out his next move.
"When an employee leaves a top AI lab, it's often into the arms of another," he wrote. "They usually rack up a huge bonus that way. That's not what I did: I didn't flirt with competitor labs."
"I'm unemployed right now," he added.