A breakthrough, maybe.

Byline: The Register-Guard

There they go again: On Monday, North Korea agreed to dismantle its nuclear programs. Then on Tuesday, it demanded that the United States first provide a civilian nuclear reactor - a sequence to which the Bush administration had not agreed and would never accept. By Wednesday, North Korea was back to accusing the United States of planning a nuclear attack, and the long hoped-for disarmament agreement seemed in danger of slipping away.

Or maybe not. Monday's agreement was not just between North Korea and the United States, but also Japan, South Korea, Russia and, most importantly, China. The other parties responded to North Korea's after-the-fact demand as boilerplate bluster from Pyongyang. China, as North Korea's primary economic lifeline and political ally, has the leverage to force North Korea back on track if necessary.

Presuming the agreement holds, the role played by China and the other three parties vindicates President Bush's insistence on six-way negotiations. North Korea had wanted bilateral talks, but the United States' range of motion is limited. The United States can threaten military action, or it can promise aid - and that's about it. China, and to a lesser extent the other three, has a wider set of options, and can make North Korea pay a price for intransigence without rattling sabers.

The agreement is comprehensive. North Korea, which credibly claims to have developed a small nuclear arsenal, has agreed to dismantle "all nuclear weapons and existing nuclear programs." What's more, North Korea said it would rejoin the nuclear Non-Proliferation Treaty, from which it withdrew two years ago, and allow inspections of its nuclear facilities. North Korea agreed to go further than it did with its broken 1994 accord, which promised only the suspension, not the abandonment, of nuclear programs.

In exchange, the other five countries promised to provide energy and economic assistance, and an end to diplomatic isolation. The United States specifically pledged not to overthrow Kim Jong-Il's regime. And the five nations agreed to provide North Korea with a light-water nuclear reactor, a civilian type suitable for producing electricity.

The sequence of these steps was left to be determined in negotiations scheduled for November. But now North Korea is insisting that it receive the light-water reactor first. The United States and its partners say their understanding is that the reactor would be delivered sometime after North Korea's disarmament promises had been kept. That reading is the only one that makes sense. The United States and the others would never agree to a key North Korean demand without concrete demonstrations of good faith.

China does not appear to regard the sequencing dispute as a serious matter. The People's Daily, the Communist party newspaper, trumpeted the agreement as evidence of China's emergence as a power in global diplomacy, declaring, "There is no turning back." Japan announced the resumption of bilateral talks the same day that North Korea made its reactor-first demand.

Yet North Korea is predictably unpredictable - and, as the 1994 agreement showed, will discard agreements after obtaining everything it can gain from them. China, the United States and the others must pressure Pyongyang to understand that disarmament is in everyone's interest and must come first.

Even then, Ronald Reagan's advice to arms negotiators applies: "Trust, but verify" - and with North Korea, trust should not extend far.