The United Nations was conceived, by us, as a supra-national government that would keep peace between nation states and other actors. The Korean War was the first major test of that hypothesis and as unsatisfying as the result might seem, it worked. The Sino-Soviet bloc was not able to invade and take over an independent nation and South Korea has developed into a first world country after being terribly devastated.
The only reason that this UN “Police Action” even occurred (as opposed to the USA going in alone to defend South Korea) is that the Soviet Ambassador foolishly boycotted the Security Council meeting that authorized it.
They never made that mistake again - a simple Soviet “Veto” would have prevented the UN from becoming involved.
A little known fact of history....
https://www.history.com/this-day-in-history/soviets-boycott-united-nations-security-council
The only reason it happened was the Soviets were stupid enough to boycott a Security Council meeting and thus not Veto the action. They never made that mistake again.
South Korea is not a nation. It is a state.
Korea is a nation, a very old one.
the only reason the that it worked was that the soviet union and its allies who had veto on the security council chose to not show up for a security council meeting... the united states in a surprise move called for a vote authorizing the police action....the Russians and the Chinese have never boycotted a security council meeting after that vote. It was the one and only time an issue of enforcement has happened against the will of the of a major world power.