What convinces is conviction. Believe in the argument you're advancing. If you don't you're as good as dead. The other person will sense that something isn't there, and no chain of reasoning, no matter how logical or elegant or brilliant, will win your case for you.
“Some day, somebody is going to have to start talking about what happens to us all a decade from now if we let these North Koreans and the Iranians go forward with their nuclear weapons program.”