The difference between aid, treaty, and alliance is aid is like the lowest level of friend ship and the people in your aid will give you the bare minimum of what you need. Treaty is like the next level of friend ship like they will supply them with troops and equipment many be even fight for them. Alliance is the best level of friendship like if someone invaded you then you alliances would invade them back and fight for you give you want you need and more.
The us is later involved in the diagram and they join the triple entente because of what Germany did. They got involved in 1917 because Germany sunk one of their ships.
The us is later involved in the diagram and they join the triple entente because of what Germany did. They got involved in 1917 because Germany sunk one of their ships.