THIS MONTH IN KOREAN HISTORY - July 2025

Written By Korean Culture Center KCC

Korea: The forgotten piece of WWII

By Sharon Stern

With wars raging around the globe and the threat of new wars looming, we decided to take a look at Korea’s experience in World War II and continued conflict leading to the Korean War this month.  War is ugly and takes its toll on mostly ordinary people, as was mentioned in the Editor’s Notes of this newsletter.  Late in the 19th century, Korea came out of its relative isolation and other countries sought influence and control over the peninsula.  Some of the moments of history summarized here have been covered in great detail in previous newsletters, but this month we are going to look at a longer timeline.  We include histories of both Japan and Russia, because both are critical to events that shape Korea.

It is really important to back up far enough in history to understand that Korea was constantly under threat of war and occupation from the late 1800s on.  The details of history can be boring to many.  Too many dates.  Too many treaties signed.  What is important is to understand that with each new invasion, Korea lost more autonomy.  With each new treaty signed, Korea had to give up more of what it was.  The ordinary people suffered.  This is what happens when countries with more military and sometimes economic or political might want to control smaller countries or groups of people or when their territory is simply in the way of a military super power.  This is what continues to happen around the world.

Pre-World War I and Annexation

Map of Korea and Manchuria. Includes index map and insets of Vladivostok and Port Arthur

Other parts of Manchuria had been ceded to Russia by the Qing Dynasty in 1860.  In 1904-1905, Russia and Japan fought the Russo-Japanese War, trying to establish control over all of Manchuria, but particularly the Liaodong Peninsula, as well as Korea.  Russia was busily building the Trans-Siberian Railway, an arm of which reached into Korea.  Russia had also built an arm of the Trans-Siberian Railway into Manchuria all the way to Port Arthur after having leased the Liaodong Peninsula from the Qing, but it was a single line and limited Russia’s ability to get supplies to their troops on the peninsula.  Ultimately, Japan pushed Russia further north.  But all of this back and forth in the immediate area should help you see why Korea was so strategic to both Russia and Japan.

Japan didn’t want to lose influence in mainland Asia.  Russia wanted to expand its own borders and continue building the Trans-Siberian Railroad.  Japan signed the Anglo-Japanese Alliance agreement in 1902, willing to acknowledge Russia’s dominance in Manchuria, if it could have its influence in Korea recognized.  However, a surprise attack by the Russian Pacific Fleet in Port Arthur on February 9, 1904 began war between the two countries.

Donuimun Gate, also known as West Gate or Seodaemun, Seoul, South Korea. Photographed 1904 by Horace Grant Underwood.

When the war started, Japan sent troops to occupy Seoul.  Korea had declared itself neutral in the war, but they signed the Japan-Korea Treaty of 1904 that stated that Korea would put its trust in the government of Imperial Japan.  However, the treaty also stated that Japan would guarantee the territorial integrity of Korea.  In addition, the treaty stated that Japan would defend Korea, but might need to occupy portions of Korea to do so.  There was another treaty signed later in the year and, therefore, further into the war, that gave Japan a stronger hand in the political decisions of Korea.  These treaties gave Japan an upper hand when negotiating the agreements in the Treaty of Portsmouth, which ended the Russo-Japanese War.

The U.S.’s president Theodore Roosevelt negotiated the truce to end the conflict between Russia and Japan.  The end of the Russo-Japanese War came on September 5, 1905, when the two countries signed the Treaty of Portsmouth in Portsmouth, Maine.  Roosevelt won the Nobel Peace Prize for accomplishing this.  Russia’s embarrassment in military defeats of the war helped lay the groundwork for the First Russian Revolution of 1905.  Russia’s interest in the region did not disappear.  This becomes a very important issue after WWII.

Korea was not present for the Portsmouth Peace Conference, and yet the trajectory for its next 40 years (and one could argue 83 years) was set there.  Twelve sessions took place before the treaty was finalized and signed.  One of the first issues settled was to recognize Japan’s claim to Korea.  The Liaodong Peninsula lease and Russia’s arm of the Trans-Continental Railroad into the peninsula were ceded to Japan.  At the end of the negotiations, it was decided that Japan would control the southern half of Sakhalin Island, which had been in Russian control, although the Japanese had invaded it several times.  The island was divided at the 50th parallel.  This island becomes important for the Korean diaspora during WWII and until today.

Japan’s dominance in Asia was confirmed as a result of the Treaty of Portsmouth, though their overextension of military efforts showed their weaknesses to Europe and the US.  The treaty acknowledge that Japan had political, economic and military interests in Korea.  Korea immediately became a protectorate of Japan.  Russia had to give up its expansion into East Asia.  In November of 1905, Japan and Korea signed the Japan-Korea Treaty of 1905, also known as the Eulsa Treaty, which deprived Korea of its diplomatic sovereignty.  Emperor Gojong had felt coerced into signing it.  He immediately tried to rescind it, but couldn’t find international backing to help him.  In 1907, Yi Chun was sent by Emperor Gojong to a peace conference at the Hague to try to get support for claiming Korea was an independent country, but Japan convinced the conference to reject the Korean delegation.  Yi committed either suicide out of shame or was killed by Japanese spies.

Modern Korean historians believe that Korea was betrayed by Roosevelt in the creation of the Treaty of Portsmouth.  Korea had signed the Joseon–United States Treaty of 1882. Article I of this treaty reads:

“There shall be perpetual peace and friendship between the President of the United States and the King of Joseon and the citizens and subjects of their respective Governments. If other powers deal unjustly or oppressively with either Government, the other will exert their good offices on being informed of the case to bring about an amicable arrangement, thus showing their friendly feelings.”

At the end of the Russo-Japan War and after the signing of the Japan-Korea Treaty of 1905, Japan established the Japanese resident-general of Korea who made political decisions and ruled the country indirectly.  In 1907, Emperor Gojong was forced to abdicate.  Korea was formally colonized by Japan in 1910 and were made to sign the Japan-Korea Annexation Treaty.

After the annexation, Japanese settlers were very interested in acquiring land in Korea and Japanese land ownership in Korea was allowed in 1906, to both individuals and Japanese corporations.  Many former Korean landowners became tenant farmers.

The Interbellum - Between World War I to World War II

WWI happened from 1914-1918 between the Allied countries of France, Italy, the UK, the US, Russia, Japan and others and the Central Powers of Germany, Hungary-Austria, Bulgaria, the Ottoman Empire and others.  Japan played a significant role in WWI.  Even though Korea had already been annexed, the war, which mostly took place in Europe, did not affect Korea directly.  Honoring the treaty it had signed in 1902, (see above) Japan helped the Allied forces.  Japan’s participation focused on taking German territories in the Pacific and China.  At the end of the war, Japan was given a mandate over the islands of Micronesia, Marshall Islands and Northern Mariana.

Japan continued trying to take territories in Manchukuo and parts of China between the World Wars, effectively giving Japan control of that area.  Because the area bordered Russia on one side, these efforts didn’t go unnoticed and would come back into play after WWII.  Border disputes between Russia and Japan continued throughout this period.  In 1922, the Washington Naval Treaty is signed, limiting Japan’s naval fleet to only about 2/3 of that of the US and Britain.  Japan sees this as a declaration of inequality and breaks away from the agreement in 1934.  From 1931 on, Japan is basically at war with China.

Russia was also a major player with the Allies in WWI.  However, internal struggles of worker and farmer discontent, food shortages, ethnic inequalities led to civil war, the breakup of the Russian Empire, the Bolshevik Revolution and the Russian Revolution of 1917, causing Russia to pull out of WWI.  In 1934 and 1937, the now Soviet Union also invaded China.  In 1922, the Soviet Union signed a treaty of trade, friendship and, secretly, military cooperation with Germany.  This cooperation lasted until 1932, when Germany ended the collaboration.  Internal clashes after this inside of the Soviet Union created by Stalin’s internal strong-armed tactics caused military disarray.  In 1941, Nazi Germany invaded the Soviet Union in what was known as Operation Barbarossa, drawing the Soviet Union into WWII.


While Japan and the Soviet Union are clashing with China over territorial expansion, Korea was trying valiantly to maintain its identity.  The occupation by Japan was well entrenched by the end of WWI.  As we covered in the March newsletter, over 7,000 Koreans lost their lives in the March 1 Movement when Koreans read a Declaration of Independence, protesting Japanese occupation.

Kim Kyu Sik in 1946

The Korean Liberation Movement spread to Manchukuo as well as Siberia.  Koreans engaged in armed struggles against the Japanese in different parts of China and the Provisional Government of the Republic of Korea was set up in Shanghai.  At the 1919 Paris Peace Conference, Kim Kyu-sik came as a representative of the Provisional Government, seeking support for Korean independence.  Unfortunately, no one took the Provisional Government seriously and continued to view Korea as a Japanese colony.

In the 1910s, Gyeongbokgung Palace was partially destroyed, as were hundreds of buildings in Deoksugung by the Japanese.  In 1925, the Korean History Compilation Committee was set up to record Korean history and, in part, supposedly demonstrated how backward Korean people were and how in need they were of modernization.  Tens of thousands of artifacts and pieces of art were removed from Korea during occupation and an estimated 81,000+ have still not been returned, some ending up in museums of other countries, including the US.

The Korean Liberation Movement spread to Manchukuo as well as Siberia.  Koreans engaged in armed struggles against the Japanese in different parts of China and the Provisional Government of the Republic of Korea was set up in Shanghai.  At the 1919 Paris Peace Conference, Kim Kyu-sik came as a representative of the Provisional Government, seeking support for Korean independence.  Unfortunately, no one took the Provisional Government seriously and continued to view Korea as a Japanese colony.

In the 1910s, Gyeongbokgung Palace was partially destroyed, as were hundreds of buildings in Deoksugung by the Japanese.  In 1925, the Korean History Compilation Committee was set up to record Korean history and, in part, supposedly demonstrated how backward Korean people were and how in need they were of modernization.  Tens of thousands of artifacts and pieces of art were removed from Korea during occupation and an estimated 81,000+ have still not been returned, some ending up in museums of other countries, including the US.

World War II 

The official beginning of World War II was in 1939 when Germany invaded Poland, but a number of major events starting in 1936 really precipitated what ended up being a world war.  The Spanish Civil War in 1936 saw both Hitler and Mussolini come to the defense of Franco.  And the Japanese full-scale invasion of China in 1937, beginning the Second Sino-Japanese War, which saw Russia lending aid to China.  Late in 1937, Japan invaded the Chinese city of Nanjing and over the course of several weeks, massacred 200,000 people and raped 20,000.

By the official beginning of the war 1939, Japan had control of a good portion of the coast of China as well as other parts of Southeast Asia, but was beginning to face resistance and pushback from Chinese Nationalist forces.  The US responded to Japanese brutality with trade embargoes and a demand that Japan exit China.  In July of 1941, the US froze Japanese financial assets.  This provoked Japan to attack Pearl Harbor.

Second world war asia 1937-1942

By 1941, Japan had taken control of French Indochine (Vietnam, Cambodia, Laos).  In 1942-1943, Japan continued its expansion, conquering Burma (now Myanmar), Malay (now Malaysia), the Dutch East Indies (now Indonesia), Singapore, Hong Kong, Rabul (now part of New Guinea), Palau, Borneo, the Philippines, Guadalcanal (in the Solomon Islands) as well as many other Pacific islands.

Once the attack on Pearl Harbor happened on December 7, 1941 and the quickly subsequent attacks on the Philippines and the British battleship the Prince of Wales, with other simultaneous attacks throughout the Pacific, attention was sharply focused on Japan and the Pacific.  The US, UK, China, Australia and several other states declared war on Japan.

Japanese officers in Korea

Korea suffered greatly under occupation during WWII.  From 1939 forward, the conscription of Japanese men to the military left labor shortages and Koreans were recruited and eventually coerced into working on mainland Japan.  By 1942, the Japanese had amended the National Mobilization Law to include the conscription of Koreans for factory and mine work in Korea, Manchukuo and Japan.  But Korean laborers were also taken to all other territories of the Japanese Empire.  An estimated 5.4 million Koreans were conscripted.  The conditions that conscripted laborers worked under have been described as both dangerous and horrific.  Many conscripted laborers sent to Pacific islands and atolls died from starvation, disease and battles of the war.  On Mili Atoll, Koreans were given what they were told was whale meat, but was actually the flesh of deceased Koreans.  When they found out and rebelled, they were massacred.  In the now country of Kiribati, only 129 of 1200 laborers survived the battle between Japanese and Americans.  10,000 Korean conscripts worked in the Aso Mine in Japan, many of whom died.  

Many Koreans suffered in the notorious Unit 731 of the Japanese Army, a chemical and biological research station where victims were tortured and the army used live vivisection to slowly kill prisoners.  The atrocities committed at Unit 731 are so horrific, they are difficult to talk about or read about.  No one that went to Unit 731 came out alive.

Hundreds of thousands of Korean women were taken to be “comfort women” in Japanese military brothels a sex slaves.  A number of them were tricked, believing that they were going to work in factories or as nurses.  Later, they were simply kidnapped.  Comfort women brothels were set up throughout the entire Japanese Empire.  Many died because of the brutal treatment.  At the end of the war, many were killed by Japanese soldiers.  Those that survived faced the stigmatism of strict Confucian codes that teach that if a woman is touched by a man, they were impure and did not deserve to live.

Late in the war, in 1944, Japan started conscripting Koreans as soldiers.  A few Koreans who served for Japan ended up with important positions after the war, including Park Chung Hee, who was a military dictator in Korea from 1961-1979.  However, the vast majority of the 200,000 conscripts were regular soldiers, serving without choice.  American soldiers encountered Korean soldiers in the Imperial Army in several locations.

Japanese Language Being Taught in Korean Schools in Korea.

The attempted erasure of Korean culture happened steadily throughout the occupation.  The Japanese taught that Japanese and Koreans had a shared ancestry, meaning that Koreans were inherently Japanese.  This was used as a justification to eliminate Korean culture, language, ethnic identity.  However, Koreans were subordinate.  Japanese used ancient mythology to justify this thinking.  The myth that Joshua highlights this month in the Literature section of the newsletter is this very myth that Japanese used to justify trying to absorb Koreans into Japanese culture.  The three-legged crow of the myth featured heavily on Japanese military uniforms. 

Although Koreans were given Japanese passports, they were not given freedom of speech or assembly.  By 1932, all newspapers in Korean were prohibited.  In the same year, Koreans were obligated to take Japanese names.

Japanese required Koreans to participate in Shinto devotions in an attempt to weaken the influence of Christianity and Buddhism.  Christian missionaries had been very successful in Korea since the 1880s and Christianity became an expression of Korean nationalism during occupation.

Koreans were conscripted for Japanese War effort. Majority of them did not make it back to their home even after the Atomic bomb was dropped, and Japan surrendered.

The war created a good portion of the Korean diaspora.  After the war, 600,000 Koreans remained in Japan, often note by choice, but sometimes because their lives had become mixed into their new home.  When control of Sakhalin Island was given back to Russia, 43,000 ethnic Koreans were not allowed to repatriate to neither Japan nor Korea.  About 500,000 ethnic Koreans had escaped into the Soviet Union after colonization began.  In 1937, they were deported to Central Asia and the majority of their descendants are still in Uzbekistan and Kazakhstan.  This arm of the diaspora is known as the Koryo-saram – you know enough Korean to figure that out!  Some Koreans who were moved to the Philippines during the war stayed there, but a larger number migrated during the Korean War.  A number also ended up in Vietnam, with those numbers increasing during the Vietnam War.

The atomic bombs in Hiroshima and Nagasaki killed many Koreans.  There were an estimated 70,000-100,000 living in the two cities that were killed.

 Post War

Immediately after the end of WWII, the United Nations was formed and the US and the Soviet Union agreed to what was supposed to be a temporary division of rule in Korea, arbitrarily divided at the 38th Parallel.  We covered this in depth in the April newsletter when talking about the Jeju Uprising.  There was no peace for a weary Korea and within a very few, short years, the Korean War broke out.  Russia’s interest in occupying Korea had never gone away and the US’s interest in controlling Russia’s control was just as strong.  Tensions were extremely high in this conflict because of the use of the atomic bomb in WWII.  This month, on July 27, we remember the 72nd anniversary of the signing of the Armistice that brought a stop to fighting in the Korean War.  The war, however, never ended.  That is a constant reminder of the fragility of peace, especially in Korea.

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