Answer:
France and Great Britain joined allies so they would have power over Germany.
Step-by-step explanation:
These allies, known as the Triple Entente ( Later on Russia joined the allies with France and Great Britain ), were created because of the fear of Germany's on-growing army.
France was scared and wanted to protect itself from Germany so France was the one who created allies with Great Britain.
The allies between France and Great Britain, the purpose, was to bring their military together to create a bigger military power over Germany.