why did us intervene in this war?
After the fall of China to the Communists, US experts on East Asia saw Japan as the critical counterweight to the Soviet Union and China in the region.
Korean War
after the fall of China to the Communists, US experts on East Asia saw Japan as the critical counterweight to the Soviet Union and China in the region. 
who was thomas j. hudner jr.? An officer of the United States Navy and a naval aviator. what was his designation? Captain. did he receive any medal? The Medal of Honor. for which war did he receive it? Korean War.
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Korean War [SEP] Factors in US intervention
Especially after the fall of China to the Communists, US experts on East Asia saw Japan as the critical counterweight to the Soviet Union and China in the region. While there was no US policy dealing with South Korea directly as a national interest, its proximity to Japan increased the importance of South Korea. Said Kim: "The recognition that the security of Japan required a non-hostile Korea led directly to President Truman's decision to intervene ... The essential point ... is that the American response to the North Korean attack stemmed from considerations of U.S. policy toward Japan." Another major consideration was the possible Soviet reaction in the event that the US intervened.