France and Spain
Great Britain and France
I'd go with France and Spain, the two European nations with the power and desire to continue colonizing the Americas. Ironically, the U.S. didn't have the naval power to enforce the Monroe Doctrine at the time in was enacted and was relying on Britain to do it for them--and Britain did, because they didn't want France or Spain to gain any more power.
Britain and France
Borders of some European nations changed. The League of Nations was formed.
Germany and Italy
The two most populous Eastern European communist nations in 1950 were the Soviet Union and Poland.The two most populated Eastern European communist nations in the 1950s were the Soviet Union and Poland.
Borders of some European nations changed. The League of Nations was formed.
Borders of some European nations changed. The League of Nations was formed.
U.S. and Britain
Britain & Mexico
Britain and France