Nobody ever said that negotiating with North Korea would be smooth and easy. So the jubilation over the deal struck recently on denuclearization of the Korean peninsula was premature. So were the hand-wringing and we-told-you-sos over North Korea’s demand a day later.

The Monday agreement signed in Beijing by North Korea, the United States and the other members of the six-nation talks was general and preliminary in its terms. But it was a true breakthrough.

North Korea committed itself to “abandoning all nuclear weapons and existing nuclear programs and returning at an early date to the treaty on the nonproliferation of nuclear weapons and to the International Atomic Energy safeguards.” In return, the United States, South Korea, Japan, China and Russia promised energy assistance.

The United States affirmed that it had no nuclear weapons on the peninsula and that it had no intention to attack or invade North Korea with nuclear or conventional weapons. The parties looked toward normalized relations and peaceful coexistence.

On a particularly ticklish point, the United States and the other parties “expressed their respect” for North Korea’s right to peaceful uses of atomic energy and “agreed to discuss at an appropriate time the subject of the provision of light-water reactor” to North Korea.

The six parties agreed to carry out the agreement in a phased manner in line with the principle of “commitment for commitment, action for action.” The timetable was left open for this step-by-step trust-building plan. Details and a timetable were to be worked out at another meeting in November.

North Korea jumped the gun the very next day with its own interpretation of the phrase “at an appropriate time.” It said the United States would have to give it civilian atomic reactors before it would dismantle its nuclear weapons programs.

The United States promptly rejected this demand. A State Department spokesman said: “This is not the agreement that they signed.” China took a calmer view, asking all sides to fulfill their promises. Seoul offered to take the lead in bridging the gap between the U.S. and North Korean views. A Japanese spokesman said that if the parties were completely at odds it would mean going back to the beginning, “but we do not believe that is the case.”

Hard-liners who never wanted negotiations with North Korea will always be quick to see any bump in the road as proof that they were right. But President Bush, who had no alternative, accepted the Chinese-brokered agreement and now must see it through to completion.

The key to success will be carefully scheduled steps, in which each side can watch the other. The goal of denuclearization of the peninsula and normalized relations, diplomatic and economic, is worth a patient effort. Whatever their spokesmen may say in the heat of the moment, both sides have an interest in making the agreement work.