Pyongyang signed onto the so-called "Framework Agreement," freezing its nuclear programs just a few months later.

But any gains quickly disappeared. North Korea has continued to pursue nuclear weapons while stoking tensions with South Korea.

Just last year, North Korea launched an unprovoked attack on a South Korean warship, killing 46 sailors. A few months later, it shelled South Korea's Yeonpyeong Island, killing four.

In addition to Pyongyang's erratic behavior, there are also political considerations for the U.S., especially as it heads into an election year.

Former Deputy Secretary of State Richard Armitage says the U.S. needs to be careful it does not give Pyongyang too much room to maneuver.

"It makes us look weak and them look strong," said Armitage. "I think the better part of wisdom is to keep our powder dry, take a deep breath and watch carefully."

For now, it seems what happens next will be in the hands of Kim Jong Il's youngest son, Kim Jong Un - a man who like his country, is a mystery to many on the outside.