Before 1945 Korea was controlled by Japan. After the Second World War, USA and the Soviet Union split Korea into two. This cause a divide in the country and another divide in the ideals. USA was preaching capitalism and democracy. The Soviet Union, on the other hand, was looking to spread communism. North Korea invaded South Korea to try to form a stable, united Korea as it was before the end of the Second World War. USA acted decisively to defend the South to stop the threat of communism and to continue their policy of containment. They did not want communism to spread. The division of Korea led North Korea to invade South Korea to obtain a united, undivided Korea. From 1905 to 1945 the Korean Peninsula was under Japanese control. During its occupation, Japan built up Korea's infrastructure, especially the street and railroad systems. However, the Japanese ruled with an iron fist andattempted to root out all elements of Korean culture from society. During this time Koreans sought to form an independent statehood. Unfortunately this led to Communists and rightists disputing over who would rule an independent Korea. The Independence Movement on March 1, 1919, was brutally repressed, resulting in the killing of thousands, the maiming and imprisoning of tens of thousands, and destroying of hundreds of churches, temples, schools, and private homes. The Korean Communist movement conducted a low-level guerrilla war against the Japanese. The Soviet Union invaded Manchuria and annihilated the Japanese. From Manchuria the Soviet Union marched on into Korea. The US President, Roosevelt, wanted to place Korea under international trusteeship. At the Tehran Conference in 1943, it was agreed upon by the allies, that Korea should be run under an international trusteeship before becoming fully independent. Stalin agreed to this and a partition was made at the 38th parallel. USA had control of the capital Seoul and also the bulk of the Korean population. The Soviets supported Communism in North Korea. Their desire in Korea derived from their desire to maintain a sphere of influence in East Asia. Kim Il Sung was appointed the leader of the Korean Communist Party when it was officially formed in July 1946. The Soviets and Communists purged all non-Communists in leadership positions from North Korea. After elections in North and South Korea both premiers thought that they were the legitimate rulers. Violent skirmishes and fights broke out along the border between North and South Korea. These events added tension to the relations between North and South Korea.