The 38th parallel north cuts the Korean peninsula roughly in half. The parallel was the original boundary between the US-occupied and Soviet-occupied areas of Korea at the end of World War II. When the Democratic People's Republic of Korea (DPRK, informally North Korea) and the Republic of Korea (ROK, informally South Korea) were created in 1948, this line became a de facto international border between the two countries. It was also one of the most tense fronts in the Cold War.