Yalu
Korea is east of the Yellow Sea, which extends into the Korea Bay, and separates Korea from China to the west.
China, Russia
During the Korean War, North Korea and China were allies, but currently they have problems with each other.
North Korea, the Soviet Union, and China
North Korea's side
The Korean Strait
The Korea Strait separates Korea and Japan. It lies between the Japanese island of Kyushu and the South Korean mainland. It is an important waterway for maritime transportation between the two countries.
North Korea has borders with both China and Russia (at Khasan). The Korean peninsula is separated from mainland China by the Korea Bay (in the north) and the Yellow Sea. (see map link)
in June 1950, North Korean troops crossed the 38th parallel that separates North Korea from South Korea and was the cause for the Korean war (conflict)
Water.
Political system
During the Korean war they were supported by China and the soviet union (the two major communist powers)