This book is intended to elucidate United States policy during the Korean War and to describe the strategies and command methods by which that policy was carried out. The major decisions that determined the United States course in Korea and continued to influence the nations responses to Communist aggression during the two decades that followed were taken during the first twelve months of the Korean fighting. Although the war continued for another two years, no significant change was made in the policy developed between President Trumans decision to intervene in June 1950 and the beginning of Armistice negotiations at Kaesong in July 1951. This book concentrates on that initial period.