In fact, the principle of the six-party talks is to settle the Korean nuclear issue, but not all North Korea-related issues. The nuclear issue belongs to the security category, and the solution to this should be limited to the security category only. Any presumption or arrangement exceeding the security framework will lead to complication. Since North Korea claimed that the reason it insisted on developing nuclear weapons was because it believed its security was threatened by the United States, the issue should be settled through a U.S.-North Korea bilateral security agreement or regional multilateral security system, which means "abandoning nuclear programs for security." This is a clear and simple problem that can easily be settled. But the North Korea-related issues are much more complicated, because they concerns differences among countries, such as historical issues, cultural traditions, ideologies, strategic interests, policies and stipulations and even long-time existing biases, which are beyond the capability of the six-party talks.

If all these issues are linked with the nuclear issue and put on the negotiation table of six-party talks, the result undoubtedly is messy. For example, developing diplomatic relations between concerned nations should be an achievement that is made after the nuclear issue is resolved, but not a precondition of solving the issue. Besides, economic aid and cooperation are expressions of friendliness after relations have been established, but not the duties of other parties. Therefore, the six-party talks should be simplified and stick to the principle of "abandoning nuclear programs for security." The negotiators should not try to settle all the related problems with one single plan.

The third is to clarify whether the nuclear issue will be partially or fully settled. During the discussions to persuade North Korea to abandon its nuclear programs, two questions should be answered. First, does North Korea have a uranium enrichment plan? If it does, should that be included in the North Korea nuclear issue framework? Second is how the related parties should deal with the produced nuclear weapons?

Regarding the first question, North Korea only admitted that it has a plutonium enrichment program, but not a uranium enrichment program (it once admitted its uranium enrichment plan in October 2002, but denied it soon thereafter). However, the United States insisted that North Korea actually has two nuclear programs. The Joint Statement reached after the fourth round of the six-party talks in September 2005 made a vague reference to this issue, saying, "North Korea promises to abandon all its nuclear weapons and existing nuclear plan." The word "existing" can be understood to have multiple meanings that either Washington or Pyongyang can define according to their own understanding. As a result, this issue will continue to be the focus of disputes in future six-party talks.

With respect to the second question, although the Joint Statement states that North Korea promised to abandon all its nuclear weapons, authoritative officials from North Korea have repeatedly claimed that the nuclear test was not conducted for the purpose of abandonment. Several years ago, North Korea hinted that it would keep one atomic bomb at least. Though North Korea agreed in this round of talks to close and seal nuclear facilities at its Yongbyon plant within two months, whether or not it will abandon its produced nuclear weapons is still unclear. The principle of the six-party talks is to settle the Korean nuclear issue and thus realize denuclearization on the Korean Peninsula. If these two questions cannot be resolved, the six-party talks actually will not reach their goal.

The fourth relates to a thorough plan to achieve denuclearization on the Korean Peninsula. Though the principle of "promise for promise, action for action" was established to solve the problem of who will take the first step when there is not enough mutual trust among the negotiators, facts have shown that this principle should be more detailed. Otherwise, the principle could lead the parties to a wrong direction. There might be some imbalance on the "promise for promise" level, but no big problems will be brought up. However, on the "action for action" level, further stipulations are needed. For example, the latest agreement stated that North Korea promised to close and seal nuclear facilities, and the other concerned parties should give North Korea energy aid as compensation. The energy aid is irreversible, but the nuclear facilities are not. If this time, North Korea's nuclear capacity can be truly disabled, the mechanism of six-party talks will make progress on maintaining a balance.

Only when these four obstacles are removed, can the six-party talks make practical and actual progress.