- North Korea, South Korea
- Korea (North) ()
The Korean War between communist North Korea, backed by China and the Union of Soviet Socialist Republics (USSR), and South Korea, supported by the USA and the United Nations, started with the invasion of South Korea on 25 June 1950. After the bitter fighting over three years ended, a ceasefire was agreed on 27 July 1953. Continuing difficulties in the relationship between the two parts of the Korean peninsular have precluded the signing of a peace treaty between the two states. Hence they are still technically at war 57 years later.