38th parallel north in the context of "Battle of Heartbreak Ridge"

The division of Korea began at the end of World War II on 2 September 1945, with the establishment of a Soviet occupation zone and a US occupation zone. These zones developed into separate governments, named the Democratic People's Republic of Korea (North Korea) and the Republic of Korea (South Korea), which fought a war from 1950 to 1953. Since then the division has continued.

By the early 20th century, both countries were one single nation: the Korean Empire. During World War II, the Allied leaders had already been considering the question of Korea's future following Japan's eventual surrender in the war. The leaders reached an understanding that Korea would be removed from Japanese control but would be placed under an international trusteeship until the Koreans would be deemed ready for self-rule. In the last days of the war, the United States proposed dividing the Korean peninsula into two occupation zones (a U.S. and Soviet one) with the 38th parallel as the dividing line. The Soviets accepted their proposal and agreed to divide Korea, which led to the declaration of General Order No. 1.

North Korea, officially the Democratic People's Republic of Korea (DPRK), is a country in East Asia. It constitutes the northern half of the Korean Peninsula and borders China and Russia to the north at the Yalu (Amnok) and Tumen rivers, and South Korea to the south at the Korean Demilitarized Zone (DMZ). The country's western border is formed by the Yellow Sea, while its eastern border is defined by the Sea of Japan. North Korea, like South Korea, claims to be the sole legitimate government of the Korean Peninsula and adjacent islands. Pyongyang is the capital and largest city.

The Korean Peninsula was first inhabited as early as the Lower Paleolithic period. Its first kingdom was noted in Chinese records in the early 7th century BCE. Following the unification of the Three Kingdoms of Korea into Silla and Balhae in the late 7th century, Korea was ruled by the Goryeo dynasty (918–1392) and the Joseon dynasty (1392–1897). The succeeding Korean Empire (1897–1910) was annexed in 1910 into the Empire of Japan. In 1945, after the Japanese surrender at the end of World War II, Korea was divided into two zones along the 38th parallel, with the north occupied by the Soviet Union and the south occupied by the United States. In 1948, separate governments were formed in Korea: the socialist and Soviet-aligned Democratic People's Republic of Korea in the north, and the capitalist, Western-aligned Republic of Korea in the south. The North Korean invasion of South Korea in 1950 started the Korean War. In 1953, the Korean Armistice Agreement brought about a ceasefire and established a demilitarized zone (DMZ), but no formal peace treaty has ever been signed. Post-war North Korea benefited greatly from economic aid and expertise provided by other Eastern Bloc countries. However, Kim Il Sung, North Korea's first leader, promoted his personal philosophy of Juche as the state ideology. Pyongyang's international isolation sharply accelerated from the 1980s onwards as the Cold War came to an end. The fall of the Soviet Union in 1991 then brought about a sharp decline to the North Korean economy. From 1994 to 1998, North Korea suffered a famine with the population continuing to suffer from malnutrition. In 2024, the DPRK formally abandoned efforts to reunify Korea.

Korea is a peninsular region in East Asia consisting of the Korean Peninsula, Jeju Island, and smaller islands. Since the end of World War II in Asia in 1945, it has been politically divided at or near the 38th parallel between North Korea (Democratic People's Republic of Korea; DPRK) and South Korea (Republic of Korea; ROK). Both countries proclaimed independence in 1948, and the two countries fought the Korean War from 1950 to 1953. The region is bordered by China to the north and Russia to the northeast, across the Amnok (Yalu) and Duman (Tumen) rivers, and is separated from Japan to the southeast by the Korea Strait.

Known human habitation of the Korean peninsula dates to 40,000 BC. The kingdom of Gojoseon, which according to tradition was founded in 2333 BC, fell to the Han dynasty in 108 BC. It was followed by the Three Kingdoms period, in which Korea was divided into Goguryeo, Baekje, and Silla. In 668 AD, Silla conquered Baekje and Goguryeo with the aid of the Tang dynasty, forming Unified Silla; Balhae succeeded Goguryeo in the north. In the late 9th century, Unified Silla collapsed into three states, beginning the Later Three Kingdoms period. In 918, Goguryeo was resurrected as Goryeo, which achieved what has been called a "true national unification" by Korean historians, as it unified both the Later Three Kingdoms and the ruling class of Balhae after its fall. Goryeo, whose name developed into the modern exonym "Korea", was highly cultured and saw the invention of the first metal movable type. During the 13th century, Goryeo became a vassal state of the Mongol Empire. Goryeo overthrew Mongol rule before falling to a coup led by General Yi Seong-gye, who established the Joseon dynasty in 1392. The first 200 years of Joseon were marked by peace; the Hangul, the Korean alphabet was created and Confucianism became influential. This ended with Japanese and Qing invasions, which brought devastation to Joseon and led to Korean isolationism. After the invasions, an isolated Joseon experienced another nearly 200-year period of peace and prosperity, along with cultural and technological development. In the final years of the 19th century, Japan forced Joseon to open up and Joseon experienced turmoil such as the Kapsin Coup, Donghak Peasant Revolution, and the assassination of Empress Myeongseong. In 1895, Japan defeated China in the First Sino-Japanese War and China lost suzerainty over Korea and Korea was placed under further Japanese influence. In 1897, the centuries old Joseon was replaced by the Korean Empire with the Joseon's last king, Gojong, becoming the Emperor of the Korean Empire. Japan's further victory in the 1904–1905 Russo-Japanese War, expelled Russian influence in Korea and Manchuria. In 1905, the Korean Empire became a protectorate of the Empire of Japan. In 1910, the Empire of Japan officially annexed the Korean peninsula.

The Korean War (25 June 1950 – 27 July 1953) was an armed conflict on the Korean Peninsula fought between North Korea (Democratic People's Republic of Korea; DPRK) and South Korea (Republic of Korea; ROK) and their allies. North Korea was supported by China and the Soviet Union, while South Korea was supported by the United Nations Command (UNC) led by the United States. The conflict was one of the first major proxy wars of the Cold War.

After the end of World War II in 1945, Korea, which had been a Japanese colony for 35 years, was divided by the Soviet Union and the United States into two occupation zones at the 38th parallel, with plans for a future independent state. Due to political disagreements the zones formed their own governments in 1948. North Korea was led by Kim Il Sung in Pyongyang, and South Korea by Syngman Rhee in Seoul; both claimed to be the sole legitimate government of all of Korea. On 25 June 1950, the Korean People's Army (KPA), equipped and trained by the Soviets, launched an invasion of the south. In the absence of the Soviet Union's representative, the UN Security Council denounced the attack and recommended member states to repel the invasion. UN forces comprised 21 countries, with the United States providing around 90% of military personnel.

The Korean Demilitarized Zone (Korean: 한반도/조선반도 비무장 지대) is a heavily militarized strip of land running across the Korean Peninsula near the 38th parallel north. The demilitarized zone (DMZ) is a border barrier that divides the peninsula roughly in half. It was established to serve as a buffer zone between the sovereign states of the Democratic People's Republic of Korea (North Korea) and the Republic of Korea (South Korea) under the provisions of the Korean Armistice Agreement in 1953, an agreement between North Korea, China, and the United Nations Command.

The DMZ is 250 kilometers (160 mi) long and about 4 kilometers (2.5 mi) wide. There have been various incidents in and around the DMZ, with military and civilian casualties on both sides. Within the DMZ is a meeting point between the two Korean states, where negotiations take place: the small Joint Security Area (JSA) near the western end of the zone.

The Korean Armistice Agreement (Korean: 한국정전협정; Hanja: 韓國停戰協定) is an armistice that brought about a cessation of hostilities of the Korean War. It was signed by United States Army Lieutenant General William Harrison Jr. and General Mark W. Clark representing the United Nations Command (UNC), North Korea leader Kim Il Sung and General Nam Il representing the Korean People's Army (KPA), and Peng Dehuai representing the Chinese People's Volunteer Army (PVA). The armistice was signed on 27 July 1953, and was designed to "ensure a complete cessation of hostilities and of all acts of armed force in Korea until a final peaceful settlement is achieved."

During the 1954 Geneva Conference in Switzerland, Chinese Premier and foreign minister Zhou Enlai suggested that a peace treaty should be implemented on the Korean peninsula. However, the US secretary of state, John Foster Dulles, did not accommodate this attempt to achieve such a treaty. A final peace settlement has never been achieved. The signed armistice established the Korean Demilitarized Zone (DMZ), the de facto new border between the two nations, put into force a ceasefire, and finalized repatriation of prisoners of war. The DMZ runs close to the 38th parallel and has separated North and South Korea since the Korean Armistice Agreement was signed in 1953.

Operation Pokpung (Korean: 폭풍 작전, lit. ''Operation Storm'') was the invasion of South Korea (Republic of Korea, ROK) by North Korea (Democratic People's Republic of Korea, DPRK) that triggered the Korean War. North Korea launched the blitzkrieg by crossing the 38th parallel north and swarming South Korea at 04:00 PYT/KST on 25 June 1950. The DPRK did not declare war before the invasion and rushed to encircle and eventually capture Seoul, the capital of South Korea, from the ROK within a week.

North Korea had mobilized for an invasion of South Korea for over year prior with support from the Soviet Union, which trained and supplied the Korean People's Army (KPA) with weapons, munitions, armored fighting vehicles, tanks, and aircraft. The vastly superiorly armed and trained KPA overwhelmed and overran the ill-prepared and underarmed Republic of Korea Army (ROKA); thus the DPRK captured Seoul within three days on 28 June.