Korea was pretty awful though.
What were we supposed to do, just let the Soviets incorporate all of Korea into their proxy sphere? Stare down the possibility of a Finlandized Japan? Unacceptable.
Korea could have been won without the mass killings of civilians resulting from bombing dams in North Korea and the extreme brutality against communities housing/supporting leftist guerrillas in South Korea committed by the Syngman Rhee regime - which the US could have influenced to some degree if not stopped all together. It is often forgotten that Korea was much worse regarding both civilian casualties and atrocities against the civilian population than Vietnam.