Japan’s rule over Korea ended with World War II, but Korea did not regain unified independence right away. Soviet forces occupied the north and U.S. forces occupied the south, using the 38th parallel as the main dividing line. This occupation split Korean politics and set the stage for competing states.
The United Nations created the United Nations Temporary Commission on Korea (UNTCOK) to help supervise elections intended to form a Korean government. Soviet authorities in the north did not allow the commission to operate there. As a result, UN-sponsored elections proceeded only in the south, deepening the political split.
Elections for a National Assembly were held in the U.S.-controlled south under UN observation. These elections were a key step toward establishing a separate southern government. The north did not participate, reinforcing the emergence of two rival political systems on the peninsula.
Following the May election and adoption of a constitution, the Republic of Korea (ROK) was proclaimed in Seoul. This created a state that claimed authority over the whole peninsula but controlled only the south. The proclamation prompted northern leaders to accelerate their own state-building steps.
North Korean authorities held elections for a new legislature, the Supreme People’s Assembly (SPA). This assembly became the central institution used to claim legal authority for a separate northern state. It also provided a platform to adopt a constitution and appoint a government.
The first SPA convened and discussed a new constitution for the northern state. The 1948 constitution established key governing structures, including the SPA’s central role in state authority. This constitutional step prepared the formal proclamation of the Democratic People’s Republic of Korea (DPRK).
The DPRK was proclaimed in Pyongyang, formalizing a separate northern government. Kim Il Sung became premier (head of government), while Kim Tu-bong served as head of state under the new system. The proclamation marked a decisive turning point from occupation-era administration toward a permanent divided peninsula.
The Soviet Union withdrew its occupation troops from North Korea in December 1948, leaving advisers behind. This withdrawal occurred after the DPRK was proclaimed and as international disputes over legitimacy continued. The end of the Soviet occupation changed the security balance and left Koreans facing each other more directly across the 38th parallel.
The UN General Assembly adopted Resolution 195 (III) on “the problem of the independence of Korea.” It recognized the ROK government as the only lawful government in Korea on the basis of UN-observed elections where they could be held. This decision widened the international legitimacy gap between the two Korean governments.
The United States completed withdrawal of its combat troops from South Korea by late June 1949, leaving an advisory presence. This reduced on-the-ground deterrence at a time of rising cross-border tensions. Both Korean governments continued to claim authority over all of Korea, making armed conflict more likely.
After the People’s Republic of China (PRC) was founded, the PRC and DPRK exchanged diplomatic recognition. This strengthened the DPRK’s position within the emerging communist bloc and increased the geopolitical stakes of the Korean divide. The relationship would become crucial once war began in 1950.
In the early hours of June 25, 1950, North Korean forces crossed the 38th parallel and began a large-scale invasion of South Korea. The attack transformed the unresolved question of Korean state legitimacy into a full war. This event effectively ended the 1948–1950 phase of state proclamation and diplomatic positioning by shifting the struggle to the battlefield.
Proclamation and International Recognition of the Democratic People's Republic of Korea (1948–1950)