South Korea is the nation that will foot the bill for most of the long-term costs when the North Korean regime fails. South Korea, together with China, will also determine how far in the future that event will come to pass. Japan does not have such a direct role to play, particularly since it already has played most of its economic chips. But no solution, final or interim, can be pursued without taking into consideration the regional security implications of Japan's very strong concerns over the dangers of a North Korea with viable WMDs.
Still, North Korea, China and the United States are the ones with the most chips at the table, and they were the ones who resurrected the Six-Party Talks. Let's take stock of where they stand.
North Korea now can make a plausible claim to have a tested nuclear explosive device in hand, and enough weapons-grade plutonium to create several nuclear explosive devices. It has gained more strategic chips. It has decided that it is time to come to the table to play its survival game.
China has demonstrated that it is willing to play the economic card. It even discreetly shut the oil valve in September, if, of course, circumstantial evidence is to be believed. Even that, if it happened, proved futile (and we do not know yet what more China did in October on oil supplies), but China did further raise the stakes in taking surprisingly stern measures after the nuclear test. China will use every reasonable means to stave off regime change in North Korea, and it has bought more time to do so by coaxing North Korea back to the table.. In any case, China has come a long, long way since it was dragged kicking and biting into hosting the Six-Party talks.
The number one priority of the United States is to stop nuclear proliferation. For them, the sky has not fallen just because North Korea conducted a nuclear test. A distant second must be stopping North Korea from engaging in counterfeiting, drug traffic, and other illicit activities. Regime change must be high on the Christmas wish list of the Bush administration, but North Korea and China (as well as South Korea) are in no hurry to oblige the US.
Going back to the other three, South Korea is welded to the status quo, its shift along the nuclear yardstick notwithstanding. Its economic chips are substantial, but they are on loan to the North. Japan may wish for regime change, but it has already played most of its economic chips. The nuclear threat is not without its silver lining for some of our "normal nation" advocates, who can use a prolonged crisis on the peninsula to press their security agenda. Russia is the closest thing to a bystander here.
The Six are not on the same page, and never will be; our interests diverge too much for that, even between Japan and the US. (In addition to the proliferation vs. suicide attack difference in emphasis on WMDs/missiles, the abductees issue continues to haunt us.) However, we all seem to be reading from the same book that brings the characters together in an uneasy equilibrium. We'll know soon if this can lead to a more stable situation in which Kim Jong-il's regime can gain a little more breathing room, while the rest of us can feel a measure of assurance that we need not fear an escalation of the North Korean WMD/missiles program nor the insidious consequences of North Korea's counterfeit, drugs and other illicit moneymaking schemes.
Intriguingly, the US has some loose change to play. The bulk of its financial sanctions were imposed against the counterfeit and other criminal activities of the Kim regime. Thus, the US can pull them back without explicitly rewarding North Korea for something a little less than a commitment to complete, verifiable and irreversible WMD disarmament. Indeed, the Three have agreed to a subsidiary working group on the financial sanctions. There are news reports from Beijing, albeit iffy, that North Korea is willing to acknowledge some non-state responsibility for counterfeit activities. If any nuclear deals are going to be cut, this is where it's likely to be.