Ha ha.
I am sure Mattis knows his guy is a nut as well. He would want to use Trump's crazy to scare them.
It's a dangerous game but leaving them to keep on developing their technology is also dangerous, and in my view more so.
A funny thing about the NK conversation is that the contemptuous talk about appeasement sorta dries up. It's easier to condemn it when it doesn't affect you. But here's a good example of why folks try everything to avoid the war.