Answer:
They feared the rising military power of Germany and sought to counter the power of the Triple Alliance.
Step-by-step explanation:
The Triple Alliance, otherwise known as Triple Entente is an agreement reached by Great Britain, France and Russia that they would each remain neutrals in wars between each other and help defend each other when attacked by external forces.
The best explanation as to why Great Britain, France, and Russia formed the Triple Entente was that they feared the growing power of Germany and sought to enter an alliance with each other.