From Evan Sarzin at The Moderate Voice:
One negotiation theory holds that your opponent will give in if you’re unpredictable, maybe really unhinged. Take North Korea, for example. Kim Jung-Un gets people thinking that he’s a rabid dog who’s broken into his master’s cocaine stash. He may say he’d drop a nuclear bomb on the US even though he knows that we’d turn the Hermit Kingdom into a radioactive sinkhole. That’s why he hasn’t done it and probably never will. The Crazy Card works only when the other guy believes it, doesn’t know when it will happen and has a lot more to lose. Still, the lunatic might extort some lagniappe, like reduced sanctions because, well, you never know.
A career spent playing the Crazy Card against banks, bankruptcy trustees and trade creditors may convince a person – maybe a real estate developer-that outrageous behavior and the threat of self-destruction will always scare his enemies into submission. When it comes to government work, though, that particular ploy isn’t transferable.