The difference between an aid, a treaty, and an alliance is:
Aid: To help, assist, support someone/group.
Treaty: A written agreement between two countries.
Alliance: An alliance is making a pact between organizations or countries to support each other and stay on each other's sides.
"A union or association formed a mutual benefit ."
*Part 2*
The U.S isn't a part of the diagram because it only shows the alliances between the countries that were originally a part of WW1.
Aid: To help, assist, support someone/group.
Treaty: A written agreement between two countries.
Alliance: An alliance is making a pact between organizations or countries to support each other and stay on each other's sides.
"A union or association formed a mutual benefit ."
*Part 2*
The U.S isn't a part of the diagram because it only shows the alliances between the countries that were originally a part of WW1.