The Korean war began on June 25, 1950, when 75,000 soldiers from the North Korean People’s Army poured across the 38th parallel, the boundary between the Soviet-backed Democratic People’s Republic of Korea to the north and the pro-Western Republic of Korea to the south. This invasion was the first military action of the Cold War. By July, American troops had entered the war on South Korea’s behalf. As far as American officials were concerned, it was a war against the forces of international communism itself. After some early back-and-forth across the 38th parallel, the fighting stalled and casualties mounted. United Nations officials worked to produced an armistice with the North Koreans in the summer of 1953, avoiding a wider war with Russia and China.