NATO (North Atlantic Treaty Organization)
Designed to counter Russian aggression after they launched their first nuclear weapons. It has worked PERFECTLY so far.
WARSAW PACT
Russia's response to NATO, but doesn't really seem to do much though since Russia invaded their own "allies"
UNITED NATIONS
The new mega league of nations designed to maintain peace in the world that is led by 2 communist countries and 3 democratic countries- no tension at all.
European Union
The European Union designed to handle affairs in *gasp* Europe such as boundary affairs and economic flow. Such a powerful system, yet by saying one word it can fall apart... BREXIT!