This Is How the Korean Peninsula Was Divided in Two The truth was that if the State Department did not clarify who would administrate which parts of Korea, then the entire peninsula would fall under the control of advancing Soviet troops. Here’s What You Need To Remember: By 1949, both Soviet and American troops had withdrawn from the peninsula, leaving behind violently irreconcilable regimes that both claimed to be the only legitimate government of Korea. A hastily conceived temporary compromise had resulted in the permanent division of a nation, and sowed the seeds for more than seventy years of conflict.