Aid is like sending food and support to another country while being neutral. This is the weakest bond.
Treaty is a formal declaration of peace on paper, a lower form of an alliance.
Alliance is a friendship between countries. This is the strongest bond.
The U.S. was not a part of the diagram because they weren't currently in the war. Eventually it does though because in April 1917 they entered the war. This is because the Lustania which was unarmed and had Americans on it was sunk.
Treaty is a formal declaration of peace on paper, a lower form of an alliance.
Alliance is a friendship between countries. This is the strongest bond.
The U.S. was not a part of the diagram because they weren't currently in the war. Eventually it does though because in April 1917 they entered the war. This is because the Lustania which was unarmed and had Americans on it was sunk.