Question: When did the country that manufactures the Koksan gun split from the country the U.S. helped in the Korean War?

<P0-S0> the lahti l-35 is a semi-automatic pistol designed by aimo lahti that was produced between 1935 and 1952. designed to be manufactured autonomously in finland, the pistol was used by finland throughout the winter war and continuation war. <P0-S1> considered to be of high quality, the lahti was well manufactured and worked reliably in cold conditions or when fouled. <P0-S2> the use of a bolt accelerator, an uncommon feature in a pistol, helped make the lahti reliable. <SEP> <P1-S0> The subsequent Korean War, which lasted from 1950 to 1953, ended with a stalemate and has left the two Koreas separated by the Korean Demilitarized Zone (DMZ) up to the present day. <SEP> <P2-S0> The U.N. demanded North Korea's immediate withdrawal and, when this was not met, United States Army General Douglas MacArthur was appointed supreme commander of U.N. forces. <P2-S1> To halt the rapid progress of North Korean forces into the south Task Force Smith was deployed to the Korean front from Japan. <P2-S2> Task Force Smith consisted of U.S. Army officers and regiments of the Army's 24th Infantry Division that were stationed in Japan as occupational forces. <P2-S3> Unfortunately the 24th were under trained, poorly supplied, and outnumbered. <P2-S4> In response to North Korea's invasion into South Korea the United Nations convened to formulate a response. <P2-S5> The 24th offered very little resistance against the North Korean advance. <P2-S6> American and South Korean troops were pushed south and in late July 1950 Task Force Smith was overrun in the city of Taejon. <P2-S7> Troops from the Army's 25th Infantry Division were deployed to Taejon to establish a new line and pullout the decimated 24th I.D. <P2-S8> This addition of combat troops did not stop the North Korean advance and both American and South Korean troops were pushed further south. <SEP> <P3-S0> on june 25, 1950, north korea invaded south korea, sparking the korean war, the cold war's first major conflict, which continued until 1953. at the time, the soviet union had boycotted the united nations (un), thus forfeiting their veto rights. <P3-S1> this allowed the un to intervene in a civil war when it became apparent that the superior north korean forces would unify the entire country. <P3-S2> the soviet union and china backed north korea, with the later participation of millions of chinese troops. <P3-S3> after an ebb and flow that saw both sides almost pushed to the brink of extinction, and massive losses among korean civilians in both the north and the south, the war eventually reached a stalemate. <P3-S4> the 1953 armistice, never signed by south korea, split the peninsula along the demilitarized zone near the original demarcation line. <P3-S5> no peace treaty was ever signed, resulting in the two countries remaining technically at war. <P3-S6> over 1.2 million people died during the korean war. <SEP> <P4-S0> The M-1978 Koksan is a 170 mm self-propelled gun of North Korean design and manufacture. <P4-S1> Very little information is available due to the secretive nature of the North Korean government. <P4-S2> The designations "M-1978" and "Koksan" were given to the type by American military analysts, as they first became aware of it in that year in Koksan, North Korea.