For years, tension between Japan and South Korea has waxed and waned in a cyclical pattern.

In the recent past, friction and animosity has repeatedly emerged as a result of the politicization of historical issues. Tension would subside only after the political winds changed to make it possible for both sides to put historical and emotional issues on the back burner to stumble forward.

So it is understandable that U.S. Assistant Secretary of Defense Randall Schriver recently said that in the past, both Tokyo and Seoul had overcome their differences and worked together on the bigger picture of regional security. “This time is no different,” he told the Center for Strategic and International Studies think tank in late August.

The problem is, this time it is different.

How different? This time, they seem to have found themselves at a diplomatic dead end with no way out. Both have boxed themselves into an untenable situation because of four elements that fundamentally shifted bilateral relations toward uncharted territory. If the current situation continues, it is not unimaginable that South Korea might boycott the Tokyo Olympics in 2020.

First, their economic relationship, which has functioned as a safety valve during challenging times, has seen its role diminished. In fact, both countries seem to have wasted their last specks of mutual goodwill and trust so that the economic aspects themselves have become the problems poisoning the relationship.

Japan downgraded South Korea as a preferred trading partner late last month, citing “security concerns.” Soon after that, South Korea took similar action and removed Japan from its list of top-tier trading partners. Neither is ready to back down anytime soon, reflecting the fundamental changes in their business relations.

Secondly, security relations, which have brought the two together in the face of common adversaries in Northeast Asia, recently underwent serious deterioration.

On Aug. 22, South Korea announced its decision to terminate an agreement that had allowed the two to share sensitive intelligence. South Korea’s decision regarding the General Security of Military Information Agreement (GSOMIA) presents a serious problem not only for military- and security-related information-sharing itself, but also for the symbolic cementing of trust and cooperation it represented between two allies of the United States.

Vice Adm. Yoji Koda, former commander of the Maritime Self-Defense Force, summarized the situation by saying: “South Korea has crossed a line that must never be crossed.”

Times have changed

Third, the two countries have become more determined than ever to redefine the fundamental nature of the relationship.

In truth, the current situation is intractable not primarily because both continue to squabble over history and emotional issues, but because they know the definition of their future relationship is at stake.

For South Korea, since its relative international standing and power gap with Japan have narrowed, it no longer feels it has to resign itself to the position of junior partner anymore. In its mind, South Korea is finally ready to correct what it considers historical wrongs imposed by Japan that exploited South Korea’s relative weakness, including the 1965 Treaty of Basic Relations between Japan and the Republic of Korea.

Japan, as a more diplomatically influential and economically advanced actor in the region, has patiently tried to manage its troubled relationship with South Korea to keep it from spiraling out of control. But as Tokyo sees it, there seems to be no way to meet South Korea’s demands, as each time Japan tries to meet them, South Korea escalates them to a higher level. The 1965 treaty, which is an official legal agreement between the two governments, is the cornerstone of the bilateral relationship for Japan.

In short, Seoul thinks it is time to stop being the lesser partner in the bilateral relationship and wants to be treated as an equal, but Tokyo has grown exasperated.

Generational gap

Fourth, the two Asian democracies seem to have exhausted goodwill and friendship at both the collective national level and the individual level, in their attempts to improve the relationship.

In both countries, the older generations of political and business leaders, who have known each other for a long time and worked together to defuse tensions in difficult times, have largely left positions of leadership.

The younger generations of political and business leaders meanwhile aren’t as familiar with each other as the previous generations were. Their view of bilateral ties is heavily influenced by the recent diplomatic and economic context. There is no indication their relationships will become close enough to play an instrumental role in managing bilateral ties anytime soon.

In a nutshell, this time is different because South Korea and Japan — in spite of their larger common regional strategic interests — have reached the point where they both see the need to fundamentally redefine their relationship but have completely different ideas and visions about it.

Ties have become so bad that South Korea and Japan seem on the verge of joining the list of the world’s most intractable neighbors in the mold of Israel and the Palestinian territories, India and Pakistan, and Armenia and Turkey, to name a few.

What Washington could do

Is there no way out? The key, as has been the case in the past, openly or not, is the United States — the chief ally and security guarantor of both countries.

Washington, however, may not be able to solve their problems. And it may seem that it is not even wise to try.

Having Washington insert itself into the fray carries high risks, as neither Japan nor South Korea want the United States to mediate per se, but rather to tell the other side why it’s wrong. As a result, Washington could further aggravate the situation and antagonize both countries by inadvertently picking sides.

Because of this consideration, Washington has exercised extreme caution to avoid further complicating the situation.

But there seems to be a consensus emerging, at least among policy experts in Washington, that standing on the sidelines wishing for good results is no longer acceptable. Ignoring the troubled Japan-South Korea relationship is only going to weaken America’s ability to meet the serious challenges in Northeast Asia, thus preventing it from advancing American interests in the region.

North Korea, Russia and China are ready to exploit the situation by further driving wedges into the three allies’ relationships.

The termination of GSOMIA has begun to affect what previously was a functional military-military relationship. As a matter of fact, there is no significant military coordination and operational mechanism available in case of a conflict between Japan and South Korea.

Fortunately, there is an indication that serious diplomatic efforts are going on behind the scenes, particularly regarding the imminent termination of the GSOMIA by South Korea on Nov. 22.

In his remarks at CSIS, Schriver indicated there was a slight possibility GSOMIA may actually survive, when he responded to a Korean journalist asking about a recent utterance by Prime Minister Lee Nak-yon hinting that Seoul may be willing to reconsider the decision.

The assistant defense secretary added that while “it is not always constructive to publicly acknowledge (when) we are addressing these very sensitive issues,” he noted the existence of “Cabinet-level engagement” efforts by Defense Secretary Mark Esper and then-National Security Adviser John Bolton — both of whom visited both capitals during the summer.

State Department Japan Desk official Jim Heller last week also noted that the United States has been actively working to resolve this issue by attempting to facilitate dialogue between the allies.

To be effective playing the facilitator’s role, the U.S. needs to walk a fine line when taking the calculated risk of pursuing deeper and more creative engagement with Japan and South Korea.

In late July, the Atlantic Council held a closed-door discussion about the steps the U.S. could take to help patch up the troubled relationship. About 20 policy experts from top American think tanks were in attendance, as well as senior diplomats.

Some of the possible solutions raised included securing a freeze on further actions that could damage relations, publishing a joint statement on trilateral cooperation, holding various high-level talks on areas of joint interest, promoting grassroots exchanges designed to promote goodwill, and promoting mutual understanding among future generations.

Ultimately, it is up to Tokyo and Seoul to get the relationship back on track.

“U.S. mediation may make the situation better, but only for a short period of time,” said Adm. Katsutoshi Kawano, former chief of the SDF’s Joint Staff. “After a while, the bilateral relationship will go back to its nadir.”

The best one could hope for, then, is for Tokyo and Seoul to manage relations with the help of Washington so that they don’t spiral out of control and further destabilize Northeast Asia.

Satohiro Akimoto is president of the Sasakawa Peace Foundation USA, an associate fellow at the International Institute for Strategic Studies’ Asia-Pacific Program, and a commentator at the Okazaki Institute.