760 United Nations Plaza, NYC, NY 10017, USA

How would the UNO have dealt with the 1936-39 Spanish War?
The same way it dealt with Korea: cut the baby in two. Then the Spanish Republic would fall apart because of the separatism of some regions, and the enmity between the Socialists, the Trotskyites, and especially the Stalinists, who had a policy that, if they were not in full control, then nobody else was. The very cunning Mr. Franco, who would have anticipated such developments, would then move in and grab the Republican territory.
How would the UNO have dealt with the 1861-65 USA War?
The same way it dealt with Viet Nam: cut the baby in two. Then the CSA would fall apart because of the fanatical devotion of many Confederate politicians to states' rights, a devotion that caused Jefferson Davis a lot of grief because several state governors refused to aid the war effort with men and supplies. The leadership of the Union, which would have anticipated such a development, would then move in for the kill.
Both civil wars would have had the same conclusion they had; they would simply have lasted a little longer.

God is subtle, but He is not malicious. (Albert Einstein)