Roh's claim that he is the mediator in Northeast Asia baffled the U.S. and China. Balancing diplomacy without the backing of power is dangerous; it would be a form of betrayal to our U.S. ally. To China, Pyongyang is a partner in security, but Seoul is a partner in convenience. If we continue to vacillate restlessly between the U.S. and China, we will lose them both.

In March 2005, President Roh Moo-hyun announced that the new basis for Seoul's diplomatic and security policies would be to play the role of mediator in Northeast Asia. In simple terms, Roh wants Seoul to carry the mantle of a being a balancing force in Northeast Asia. In even simpler terms, Seoul wants to maintain the equilibrium between the U.S. and China. For one to balance relations between two powers, one generally must have enough power or sway to influence the two parties. It was rather obvious that this declaration by Seoul – which is not capable of following through on its claim about balancing relations – baffled Washington and Beijing alike.

During and after his election campaign, Roh’s foreign policy could be summarized as saying, “So what if we don’t do what the U.S. wants us to do,” and Roh did not seem to think that the U.S. would view such a policy as favoring China. In turn, Richard P. Lawless, then deputy under secretary of defense for Asian and Pacific affairs, visited the South Korean ambassador to the United States and issued a scolding remark: “Do tell us whenever you wish to change your ally. We will honor that wish.”*

Roh Moo-hyun is not the only one who has gone through this phase. Most South Korean presidents, still feeling high from their election victories, fall for the delusion that Seoul can take an active role in bringing peace to an unstable Northeast Asia. Roh Tae-woo’s “Consultative Conference for Peace in Northeast Asia,” Kim Young-sam’s “Northeast Asia Security Dialogue” and Park Geun-hye’s “Northeast Asia Peace and Cooperation Initiative” all arose from such illusions. President Park Geun-hye, whose pro-China policy was rather apparent during the early parts of her term, stood side-by-side with President Xi Jinping and President Vladimir Putin at Tiananmen Square in September 2015. This was the final nail in the coffin for the U.S., and the beginning of its closer cooperation with Japan.

In the case of leftist-liberal administrations, the anti-U.S. sentiment of the South Korean liberal movement causes them to take pride in distancing themselves from the U.S. alliance. And in doing so, they have overlooked two important points. One is that the South Korea-U.S. alliance is not a constant. Despite the rhetoric of an “alliance forged in blood,” the relationship cannot stand without each ally carrying out its duties and responsibilities.

The second point is that China is an ally of the enemy. In accordance with the Sino-North Korean Mutual Aid and Cooperation Friendship Treaty of 1961 which is still in effect, China must provide military assistance, including troops, to Pyongyang in the event that war resumes on the Korean Peninsula. This is famously known as the “automatic involvement clause.” It means that China can suddenly become an enemy state if its hand is forced.

China has traditionally considered North Korea as its buffer state, and became involved in the Korean War because the survival of North Korea suited its security and national interests. To China, South Korea is a partnership of interests and North Korea is a partnership in security. Interests may be set aside for something else, but security cannot. The nature of the Beijing-Seoul relationship is starkly represented by the “garlic crisis”** protest in 2000 and the recent THAAD protests.***

In diplomacy, the role of mediator goes to the power that can force a military balance. Such was the case of the United Kingdom, which maintained the balance of power in 19th century Europe. If a country that does not have the capability or willingness to enforce a military balance performs this function, it will be nothing short of walking a tightrope. And tightrope walking can lead to a fall. More than anything, in order to conduct balanced diplomacy, the state must not have an alliance to begin with. Just like the U.K. back then, seeking to be a balancer while in an alliance is an act of betrayal to one's partner.

The alliance cannot be neutral. Some argue that we should rely on the U.S. for security and that we must still maintain balance between the U.S. and China in terms of diplomacy. But for a country like ours which relies on the U.S. for its security, separating security and diplomacy is impossible. In that case, we are left with three options: 1) strengthen the South Korea-U.S. alliance; 2) annul the American alliance and assume the role of mediator between the U.S. and China; or 3) annul the alliance with the U.S. and form a new one with China. Looking at the options, our path becomes clearer. Not many experts would disagree that if we were to choose the second or third option, instead of the first, what we would gain from China would be incomparably smaller than what we would lose from the U.S.

For President Moon, whose visit to China is scheduled on Dec. 13, there is a lesson to be learned from history and a oft-repeated mistake to avoid: Moon should not stand on the bedrock of the South Korea-U.S. alliance looking for an alternative rock to stand on. China, after indiscriminate THAAD retaliations, now demands the “3 No’s,” which could easily veer off into a violation of our sovereignty.**** This means that China considers South Korea the weakest link of the U.S.-South Korea-Japan triangle, and intends to shake it. If China considers South Korea as something it can pursue when it wants, and if we do not find our proper place between the U.S. and China, we will end up losing them both.

*Editor’s note: This quotation, accurately translated, could not be verified.

**Translator’s note: The “garlic crisis” refers to the trade dispute between China and South Korea after the Uruguay Round (which led to the creation of the World Trade Organization). After the influx of cheap Chinese agricultural goods, the South Korean government at the time enacted a safeguard by raising tariffs, which prompted China to take retaliatory measures.

***Editor’s note: THAAD refers to the Terminal High Altitude Area Defense system, an American anti-ballistic missile defense system designed to shoot down short, medium, and intermediate range ballistic missiles in their terminal phase (descent or reentry) and to be implemented in South Korea. China views THAAD as a threat to its own military operations and has consequently used economic retaliation against South Korea.

****Translator’s note: China’s “3 No’s” are: no additional THAAD deployment in South Korea, no missile defense agreements between Washington and Seoul and no triple alliance between South Korea, the U.S. and Japan.