You put out a statement explaining that all leaders who don’t seize means of production and begin to work towards communism will be killed. You have 24 hours. Go down the list. Likewise to people who don’t immediately denuclearize except for DPRK. Eventually you’ll get those in power to be scared enough to start making serious concessions.
You make the person who’s dying give the statement, since you can kill them anyway you want. After enough deaths they’ll start to listen.