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[Bookmark] South Korea and Japan’s Animosity: Region’s Problem, America’s Headache

Logic suggests Japan and the Republic of Korea (ROK) should cooperate well. Emotion ensures that they don’t. Here’s why this poses a security problem for the entire region.





Bookmark is a JAPAN Forward feature that gives you long reads for the weekend. Each edition introduces one overarching thought that branches off to a wide variety of themes. In this article, we explore the ongoing issues in the relationship between Japan and South Korea, where they are heading, and what might help. Our hope is for readers to find new depths and perspectives to explore and appreciate.


For years, American diplomats and military leaders have been asking the South Koreans and the Japanese, “Can’t we all just get along?” 

The answer is, “No” — at least according to Lee Jae Myung, the ruling Democratic Party’s candidate for the 2022 South Korean presidential election. In a recent interview, he ruled out the possibility of a United States-South Korea-Japan military alliance, adding that South Korea “needs to be prepared in the event Japan’s dream of continental expansion erupts militarily.”

The headaches continue for the Americans. 

outh Korean President Moon Jae In, U.S. Vice President Mike Pence and Japanese Prime Minister Shinzo Abe, at the 2018 Pyeongchang Winter Olympics, South Korea. (Bae Jae-man/Yonhap via AP)

Common Interests

Logic suggests Japan and the Republic of Korea (ROK) should cooperate well. 

Emotion — sometimes stoked by outside actors with their own agenda — ensures that they don’t.

Leaving aside the threat from China, South Korea and Japan face common and immediate threats from North Korea. The ROK faces a serious conventional and nuclear threat, and Seoul is within artillery range of North Korean batteries. Meanwhile, as Pyongyang repeatedly reminds Tokyo, Japan is well within North Korean missile range. 


South Korea and Japan also have intertwined economies, and considerable familial and cultural connections.

Yet, the Japan-South Korea relationship resembles the difficult relationship between the Irish and the English. Resentments die hard, owing to the often cruel experience of the English colonization of Ireland centuries ago, lasting until the early 20th century. 

In South Korea’s case, the historical touchstone period is 1910 to 1945, when Japan colonized the Korean Peninsula, though Koreans claim Japanese torment of Korea goes back much farther.

South Koreans protest wartime workers in Japan.

South Korea and Japan aren’t the only countries with deep-rooted “issues.” But both are key U.S. allies — covered by treaty obligations — in a part of the world where the United States has deep interests and faces dangerous threats. 

Besides the North Korean threat, the U.S. is also squaring off with China. Indeed, the PRC is looking to dominate the Asia-Pacific and drive the U.S. off the peninsula and out of the region, making it easier for Beijing to dominate Japan, South Korea, and everyone else.

RELATED: Biden Stands Firm During Conference Call with Xi, as Security Tensions Mount in Asia

Given the seriousness of the threats, from the point of view of Washington, the “my enemy’s enemy is my friend” logic should trump historical animosity the way the threat of the Soviet Union brought post-War France and West Germany closer together. One understands Washington’s frustration with Seoul and Tokyo’s inability to get along. 

Kim Jong Un with North Korean military

Future Korean Peninsula Conflict

Whether triggered by North Korea alone or North Korea (at the very least) backed by China, war on and around the Korean Peninsula will be bloody.

The United States will have its hands full and doesn’t want to play marriage counselor between the Koreans and the Japanese. 

Inter-Korean Liaison Office is blown up by North Korea

To fight, much less win, a conflict against North Korea depends on access to bases in Japan to provide essential logistics support and facilitate troop movements. Combat operations, particularly aerial and naval sorties, will be launched from bases in Japan. The seven United Nations Command-Rear bases in Japan are indispensable. And “regular” Japan Self-Defense Force bases will also be supporting the fight — as will the JSDF itself. 

To improve the odds and to prevail at the lowest cost in lives, the Japanese and South Koreans need to coordinate defense activities with the Americans in a three-way partnership. It need not be a formal alliance.

Mobile Missile Launchers Used in North Korean Ballistic Missile tests

But all this needs to be worked out beforehand — not once the shooting starts, or with the Japanese and the South Koreans “talking through” the Americans. 

A few examples of needed cooperation: 

  1. Three-way sharing of intelligence to establish a real-time common operating picture for US, ROK, and Japanese forces.
  2. Linked missile defense systems. The missile threat to both South Korea and Japan (and U.S. bases and forces in both nations) is steadily increasing. U.S. territory, such as Guam, is also within range of North Korean missiles. It’s much worse when Chinese missiles are added in. 
  3. Joint operational talks and planning between the three nations, particularly to allocate roles and establish operational procedures on or around the Korean Peninsula.
  4. Joint cyber security and cyber defense/offense operations.
  5. Non-Combatant Evacuation (NEO) planning and exercises.
  6. Exercising and training for all the above.

RELATED: Japan Must Expand Ways of Responding to Rising Taiwan Tensions

Pictured left to right; RFA Tidespring, JS Izumo, HMCS Winnipeg, HMS Queen Elizabeth, HMS Defender, JS Ise, and the HNLMS Evertsen. UK Royal Navy Carrier Strike Group 21 HMS Queen Elizabeth, HMS Defender in the Pacific Ocean, Sept. 2021. (UK Ministry of Defense via AP)

Precedent for Cooperation

U.S. forces have been stationed in South Korea and Japan for well over half a century. The Americans have solid long standing bilateral (though not triangular) relationships with both ROK and Japanese forces.

Also, South Korean forces have engaged with Japanese forces in the past. Most recently they worked with the Japanese military as part of North Korea sanctions enforcement efforts. And earlier this year, the ROK Navy exercised with the Japanese Navy in the South China Sea, along with the U.S. Navy. 

The South Koreans and Japanese have also conducted high-level defense talks, though usually with the Americans present and organizing the meetings.

At least one South Korean army has had a counterpart relationship with a Japan Ground Self-Defense Force regional army, and study tours by officers have gone in both directions. Defense attachés are posted respectively in Seoul and Tokyo.

Protester oppose the GSOMIA intelligence sharing agreement and the visit by U.S. Secretary for Defense Mark Esper in Seoul, South Korea, Nov. 15, 2019. (AP Photo/Ahn Young-joon)

South Korea also belongs to a three-way intelligence sharing deal with the Americans and the Japanese known as GSOMIA (General Security of Military Information Agreement) that lets South Korea and Japan share information about North Korea’s military and nuclear activities directly with each other.

However, the benefits of that cooperation are not widely celebrated in the local media, and Chinese Communist Party-linked political warfare tries to undermine any rapprochement. 

At the same time, some political leaders do Beijing’s heavy lifting by looking for reasons to scale back cooperation, and vilify the other country. 

President Trump and President Moon of South Korea (AP Photo/Jacquelyn Martin, Pool)

South Korean President Moon Jae In came within days of pulling out of GSOMIA with the Japanese in 2019. He relented only under heavy American pressure.

RELATED: U.S. Says ‘Fallback Options Don’t Count,’ Urges Seoul to Restore Intelligence Pact with Tokyo

Despite these examples of ROK-Japan defense cooperation, the relationships are limited and somewhat “forced,” rather than based on a genuine desire to cooperate against recognized threats. 

South Korean protesters stage a rally to denounce Japan's new trade restrictions on South Korea in front of the Japanese embassy in Seoul, South Korea, Saturday, Aug. 3, 2019. Japan's Cabinet on Friday approved the removal of South Korea from a list of countries with preferential trade status, prompting retaliation from Seoul where a senior official summoned the Japanese ambassador and told him that South Koreans may no longer consider Japan a friendly nation. The placards read: "We denounce Japanese Prime Minister Shinzo Abe." (AP Photo/Ahn Young-joon)
South Korean protesters in front of the Japanese embassy in Seoul. Photo /Ahn Young-joon)

How Deep is the Animosity?

It’s deep. Each side thinks it is aggrieved more than the other.

Japan feels like it has made reparations and apologies — and has already reached an agreement with South Korea on a “full and final” settlement of differences (more than once). Tokyo complains the Koreans keep asking for another apology.


Tokyo is also irked that South Korean administrations periodically play the “Japan card” as a way of drumming up domestic political support.

South Koreans falsely portrayed this picture of a Meiji era coal mine worker in Japan as a wartime Korean worker in a coal mine.

And during the Moon administration, South Korean courts awarded damages against Japanese companies for using Koreans as forced labor during World War II — despite a 1965 bilateral agreement settling such claims.

The “comfort women” issue is another perennial cudgel used against Japan — as Tokyo sees it — as are complaints about Japanese politicians visiting Yasukuni Shrine. And there is South Korea’s rubbing of Japan’s noses in the Dokdo/Takeshima island issue — Japanese territory (according to Tokyo) that the Republic of Korea seized from a weakened postwar Japan. 

South Korean parliamentarians land on Takeshima.

Meanwhile, South Korea reckons it is “right” about all the things the Japanese complain about. In fact, it is risky for anyone in South Korea to publicly suggest otherwise. 

RELATED: [Bookmark] In South Korea, Lew Seok-choon Case Sparks Crisis in Academic Freedom

While South Korean “leftist” administrations most readily and forcefully play the Japan card, conservative administrations do as well. And such demagoguery is effective.

Even Koreans who understand the nation’s broader geopolitical interests and the need to prioritize a secure future over past resentments often can’t help themselves. 

To quote one U.S. Marine officer who spent many years in Korea, “The Japanese bring out the worst in the Koreans.”

U.S. President Joe Biden and South Korean President Moon Jae-in hold a joint news conference at the White House, May 21, 2021. REUTERS/Jonathan Ernst

The Americans are exasperated. They need all the help they can get. 

But Washington can’t just tell each side, “Get over it.” It is not that easy. For decades after the American Civil War, animosities lingered in parts of the United States, and many older Americans still resent the Germans and Japanese for World War II.

But one does wish for more introspection from both South Korea and Japan.

The Japanese colonial era inflicted much human suffering. 


But it is worth remembering that Japan was punished for its behavior that led up to the war with the Americans: more than 3 million Japanese dead. Every Japanese city of consequence in ashes. Nuclear bombs dropped, with radiation sickening survivors for generations. Japan was occupied by a foreign force that is still in Japan. And Japan had to provide its own “comfort woman” scheme for the occupying forces.

A Vietnamese victim of South Korean military violence takes her fight to South Korea.

And while Korea suffered mightily at the hands of the Japanese, one might also consider World War II allied prisoner-of-war accounts of extraordinary brutality by Korean guards in the Japanese-run POW camps. And just 20-plus years afterwards, South Korean troops in South Vietnam had a sometimes nasty reputation for massacring Vietnamese civilians and murdering prisoners of war. No apologies have been forthcoming.

One is inclined to despair about prospects for the Koreans and Japanese getting along anytime soon, or even over the next hundred years.

But stranger things have happened. Consider the French and the Germans — fighting three ferocious wars between 1870 and 1945 — yet coming together in the 1950s to lay the groundwork for what became the European Union. And even the British and Irish governments and Sinn Fein (the Irish Republican Army or IRA) reached an agreement to end a decades-long (the IRA would have said “centuries long”) war in 1998.

Statesmanship was required to solve these seemingly intractable problems. In other words, leaders who could put the past into the corner and figure out ways to resolve differences for a greater good.

Yoon Suk Yeol, candidate of the main opposition People Power Party (AP Photo/Lee Jin-man)
Lee Jae Myung, candidate for president from the ruling Democratic Party REUTERS/Kim Hong-Ji

A More Active U.S. Role is Needed

To help these “statesmen” emerge, the Americans could play a more active role in soothing the South Korea-Japan relationship.

However, the United States has avoided getting involved in South Korea’s domestic politics. 

So, while the Americans remained mute, South Korean administrations and politicians have too often been able to stoke anti-Japanese resentments for political advantage.

In other words, South Korean politicians get the votes while hampering America’s ability to deter war or to fight a war. Yet, they expect the Americans to fight and die on South Korea’s behalf and potentially to risk North Korean missile attacks — and, one day, nuclear attacks on American cities.

This has also made it harder for Japanese leaders who might otherwise be inclined to make concessions. And it serves as a convenient excuse for some Japanese leaders who don’t wish to make concessions.

Marines of the U.S., left, and South Korea wearing blue headbands on their helmets, take positions after landing on a beach during the joint military combined amphibious exercise.

The Americans have considerable capital in South Korea, not least as a security guarantor. So it should speak up and quietly (or not so quietly) insist on at least grudgingly improved bilateral relations. And this should include military cooperation between the South Korean and the Japanese militaries, as part of an informal (and unstated) trilateral defense scheme for the Korean Peninsula.

Washington should keep in mind that public opinion polls in South Korea reveal overwhelming support for the ROK-U.S. alliance and the American military presence. 

These poll results are telling, given that South Korean extreme leftists (known as “Jusapa”) who dominate the Moon administration are fundamentally anti-American, and pro-North Korea. They typically see the United States as an occupying force and as the reason the peninsula and Koreans are divided. Jusapa views the Japanese as American lapdogs. 


If the Americans speak up, the Jusapa may not like it, but a majority of South Koreans just might. 

And another note of caution: even pro-American South Koreans need to be careful about letting resentment of Japan get out of hand. Besides harming defense capabilities, many American citizens (and voters) might question why U.S. troops should fight and die on South Korea’s behalf if Koreans won’t fully cooperate with the United States.

As for Japan, the Americans are similarly committed to dying for Japan and need to request that the Japanese government bend over backwards (even if it feels like “once again”) to try to sort this out.

Elder Statesman and former Japanese PM Shinzo Abe and South Korean President Moon Jae In.

Of course, it often takes generations to get over history. And even then, memories linger. 

But wallowing in resentment is no more productive for governments and nations than it is for individuals. 

One hopes for South Korean and Japanese leaders to come along who speak up for a cooperative present, rather than ones like Lee Jae-myung, who seem to be trying to recreate the past through divisive statements about the future. 

Japanese Prime Minister Fumio Kishida
South Korea's President Moon Jae In. (Jung Yeon-je/Pool Photo via AP)

And since the United States is footing the bill for both countries’ freedom — to be paid in American blood (again) — the U.S. government should at least speak up and request some statesmanship.

RELATED: A Look at the Impasse Between Japan and South Korea


Author: Grant Newsham

Grant Newsham is a retired U.S. Marine and a former diplomat and business executive who spent many years in Asia. He is a senior fellow with the Center for Security Policy.


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