The letter highlights tensions within Google between its AI division and its cloud business, which sells AI services to militaries. At the company’s flagship Google I/O conference earlier this year, pro-Palestine protestors chained together at the attendee entrance, protesting Lavender, “Where’s Daddy?” software, the “Gospel” AI program, and Project Nimbus.

The use of AI in warfare has spread rapidly, pushing some technologists who build related systems to speak out. But Google also made a specific commitment: when it acquired DeepMind in 2014, the lab’s leaders required that their AI technology would never be used for military or surveillance purposes.