Only stays up for a few months?
Sounds like a decent plot for a movie. A rougue country sends 3-4 of these up over the course of a few weeks, with lifespans of a few months.
Once they are all up, tell the world that unless we are paid $2 billion for each one the nukes on them will stay armed. And let the chips fall where they may. (Would need to be a movie though, as I imagine they would burn up on reentry anyway.)
Besides, weaponized uranium or plutonium are very heavy, so doubtful they could launch it.
2 billion Yuan GB Pounds or Swiss Franks, you mean.