It will take a combination of diplomacy and blunt threats.
If Pyongyang eliminates its plutonium production enterprise, as it promised in exchange for being removed from the US State Department's terrorism-sponsor list, it will be one for the history books. It also will be the Bush administration's crowning foreign-policy achievement, but at a price. Kim Jong Il beat President Bush at the nuclear game: He built, tested, and kept the bomb.
The North never disassociated security and political leverage with nuclear weapons elimination as did South Africa, Ukraine, Belarus, and Libya. On top of that, the Stalinist regime's persistent backsliding gave clues to the difficulty US diplomats would face in attempting to get Pyongyang to abide by its 2005 denuclearization declaration.
Now North Korea's requirement that only "mutual agreement" will permit inspection of suspect atomic sites suggests that little nuclear disarmament beyond identified nuclear sites is in the offing.