Here is a media leak if true that provides some insight into the US negotiating strategy in regards to the modifications the US wants in the US-ROK Free Trade Agreement:
A number of senior officials and cabinet secretaries were present for the conversation, including Defense Secretary Mattis, Agriculture Secretary Perdue, and Secretary of State Tillerson. At issue was whether the U.S. would withdraw from the Korean trade deal — an action Trump threatened but still hasn’t done.
“You’ve got 30 days, and if you don’t get concessions then I’m pulling out,” Trump told Lighthizer.
“Ok, well I’ll tell the Koreans they’ve got 30 days,” Lighthizer replied.
“No, no, no,” Trump interjected. “That’s not how you negotiate. You don’t tell them they’ve got 30 days. You tell them, ‘This guy’s so crazy he could pull out any minute.'”
“That’s what you tell them: Any minute,” Trump continued. “And by the way, I might. You guys all need to know I might. You don’t tell them 30 days. If they take 30 days they’ll stretch this out.” [Axios]
First of all conversations like this should not be leaked out of the White House. These leaks have to stop. Secondly as the article states the crazy approach only works if people think you will actually follow through with the threat. That is why Kim Jong-un’s rhetoric is taken so seriously.