For him, not just from guess but from a lot of study, he is actually a sane guy. He's smart, intelligent and is very alert. He suffers from the Napoleon complex which explains his strange shoes, strange hair and attire.
I can't tell you who, but I have talked to people who have actually met him. And the responses are the same: This guy is smart. He's well versed about the world. Only amateurs believe otherwise... purely because of his looks.
Remember he's survived many attempts on his life. You can't do that if you're an idiot.
Right now his goal is to stay in power and keep his military happy so they don't overthrow him. Unifying Korea is only their goal on paper, but not an actuality. The North Koreans know that if there is a war, they will lose. That's why no one in South Korea right now believes there will be a North Korean invasion any time soon. People believe that for different reasons.
Some believe it is because the North too feels we're long lost brothers and that we must reconciliate and that the North Koreans would never pull the trigger on South Koreans. These people need to be checked into a mental institution.
Others, including myself, believe it's because an invasion is no longer practical for North Korea.
Kim Jong-il knows all this.
He's a smart guy.
And he is also evil.