If the United States government wants to use ChatGPT on sensitive information, I'm pretty sure that it can come to some kind of contract with OpenAI to set up their own private cloud thing dedicated to that.

I get that maybe this guy just wanted some kind of one-off use, but then arrange to have something set up for that.

EDIT: To clarify, set up for that sort of thing, not this specific use. Like, have a way to throw up secure, temporary setups for particular users who just need one-off stuff for sensitive material.