Tbh, if the other country's rulers were smart, they wouldn't think of doing anything to someone dear to our mc. Like what would be the point of turning someone that strong from a neutral position to an antagonic position to their countries.
The spy already said that his superiors weren't listening to information from the field and that they wouldn't accept negative results.
Also, when asked what she would need to do, why not say nothing? While getting a military weapon is nice, taking away an enemies military weapon is also good
By the same token, I think the Spy made the right call, because it sounds like his superiors wouldn't be willing to accept simply removing her from the field, they'd demand she actually help them, and it's better to just tell her that up front, rather than claim she won't have to do anything and risk her feeling like she was tricked when the higher-ups get pushy.
Also, while it might make logical sense for them to be happy with her simply doing nothing, "We'll give you anything you want in exchange for nothing." sounds like a scam. Demanding something of her can make the offer seem more genuine and, even if she refuses right now, building up a good relationship with her is more important in the long run.