The Triple Entente was a major part of World War One because these countries made up an entire fighting force. Germany and it's allies made up this group. The Triple Entente fought is also known as the Central Powers.
Well, there were two alliances: triple entrente and the triple alliances. I think the reason between the triple entrente and the central powers may well be that the countries that signed an alliance in the triple entrente, could be central countries or have central empires.
They joined the army as nurses and hospital workers.
The army needed to train a large force quickly.
Make it impossible for future world wars too begin