Or a bit more concretely-- what was the Soviet Union's reaction? I'm sure that the involvement of the UN fighting against the Soviet-backed North Korea was controversial, but how did this change the wider world of international diplomacy?
Basically the Soviets were boycotting the Security Council at the time so when Resolution 84 was voted on they were not there to Veto it. The Soviets had been ordered to not go to meetings by Stalin after a series of disagreements, most notably the PRC/ROC issue of who should hold the seat.
After that every Security Council member made damn sure they had somebody there at the meetings in order to Veto anything they needed.