On December 20, an advanced P-1 maritime patrol plane of the Japanese Self Defense Force was patrolling international waters between the Korean peninsula and the Japanese archipelago when its radar warning system abruptly began chiming.

The anti-submarine jet had apparently detected the fire-control radar of the South Korean destroyer Gwanggaeto the Great, cruising 110 miles west of the Liancourt Rocks. The 3,300-ton Gwanggaeto is the lead ship in her class and is armed with medium-range Sea Sparrow missiles for air defense out to ranges of twelve miles.

South Korean defense officials claim the destroyer’s higher-resolution three-dimensional STIR-180 fire-control radar—usually used to target missiles—was supplementing its surface-search radar while attempting to assist a North Korean fishing boat which had issued a distress call after running adrift. According to South Korean account, the STIR-180 was scanning in a 360-degree arc and was not focused onto the P-1.

The P-1 patrol plane broadcast a message in English to the South Korean vessel: “Korean naval ship, Hull number 971. We observe that your FC [fire control] antenna is directed to us. What is the purpose of your act? Over?”

Receiving no response, the P-1’s pilot repeated the inquiry five more times over the following six minutes. During that time, the jet circled the destroyer at altitudes as low as 150 meters.

Three days later, the Japanese government released a recording by the P-1 here, including the chatter by the crew, and demanded an apology.

Then on Friday, December 4, 2019, the South Korean government released its own video suggesting the Japanese messages were unintelligible and that the P-1 had circled provocatively low over the destroyer. At the very least, it seems unlikely the P-1 crew would have continued orbiting the destroyer if it thought it was under genuine risk of attack.

Focusing on the exact technical systems at play or the precise motivations of the crews on the destroyer and patrol plane, however, is missing the forest for the trees. Neither South Korea or Japan is seeking an armed conflict. However, militaries cohabiting international waters are capable of downplaying or covering up faux pas when they wish to do so, particularly when they are allied in a common cause such as defense against nuclear-armed ballistic missiles from North Korea. Several retired military officials have informally indicated the incident shouldn’t be made out to be such a big deal.

Instead, first Japan and then South Korea have chosen to escalate the diplomatic conflict while using accusatory language and issuing demands for apologies. This is due to a combination of unresolved historical tensions related to Japanese colonial occupation of Korea, nationalistic theater designed for domestic consumption, and genuine divergences in foreign policy.

Japan effectively turned Korea into a Japanese colony between 1876 and 1910. After the Japanese defeat in World War II, the nation was split into its present divided status. During the war, Koreans had been forced to labor in factories and serve as sex slaves (“Comfort Women”) in support of the Japanese war effort.

Though Tokyo has at times apologized for various atrocities its forces undertook in the first half of the twentieth century, these acts have been undermined by a consistent drive by Japanese nationalists, including Prime Minister Shinzo Abe, to redefine events such as biological weapons testing on civilians, the mass rape and murder of Chinese civilians in Nanjing, or the forced recruitment of sex workers under conditions that killed thousands of them, as ordinary wartime acts no different than those undertaken by the Allies in World War II.

For example, in article on October 2018, the Japan Times, apparently due to political pressure, announced it would stop using “potentially misleading” terms such as “slave or forced labor” or “Comfort women,” instead using “wartime labor” and “women who worked in wartime brothels”—arguing this was justified because in some cases the labor was voluntary.

South Korean president Moon Jae-in recently terminated cooperation with a Japanese foundation intended to support surviving comfort women over continued disputes on how such wartime acts are portrayed, underscoring how contentions over the narrative itself may be important than material compensation alone.

The Abe government, meanwhile, may have an incentive to escalate tensions with South Korea to shore up his credentials from his party’s right wing after loosening of labor-migration laws implemented to address a shrinking labor force.

Despite the historical headwinds, Japan and South Korea should have highly practical reasons to cooperate. Both are wealthy democracies that are potential targets of North Korean nuclear missiles, both host U.S. military bases that contribute to each other’s security, and both are wary of pressure from Beijing’s growing economic and military might.

However, Tokyo and Seoul also espouse sharply divergent strategies regarding North Korea. The left-wing Moon administration seeks a new peace with North Korea buttered over with generous economic assistance, while tacitly overlooking the North’s retention of nuclear weapons capability. Meanwhile, the right-wing Abe administration has advocated greater military and economic pressure on Pyongyang to denuclearize and has sought a rapid buildup of Japanese military capabilities, including stealth jets and aircraft carriers.

After escalating tensions with North Korea for a year and a half, the Trump administration declared victory after a symbolic summit in Singapore in 2018 and has remained largely disengaged from the two Koreas ever since. Washington’s disinterest suits Moon’s peace agenda, but not Abe’s desire for more sanctions and military buildup. The United States’ political disarray and relative absence from northeast Asian politics have also removed a typical stabilizing force on relations between the two countries.

It’s worth noting that the islands, known as Takeshima by the Japanese and the Dokdo by Koreans, are also subject of a dispute between Seoul and Tokyo, but remain under South Korean control. In August 2018, Japanese textbooks formally described the South Korean presence as an “illegal occupation,” triggering yet another a diplomatic spat.

The lingering tensions between the two nations highlight how heavily historical scars can affect the ostensibly dispassionate pursuit of international interests.

Sébastien Roblin holds a master’s degree in conflict resolution from Georgetown University and served as a university instructor for the Peace Corps in China. He has also worked in education, editing, and refugee resettlement in France and the United States. He currently writes on security and military history for War Is Boring.

Image: Wikipedia.