What role did France play in the American Revolutionary War?

France played a critical role in the American Revolutionary War by providing military assistance to the American colonies. After initially being supportive in favor of independence due to their rivalry with Britain, France formalized their involvement by signing the Treaty of Alliance with the United States in 1778. This agreement brought French troops, naval support, and financial aid to the American cause, which were instrumental in key victories, such as the Battle of Yorktown in 1781. The French navy's involvement not only helped to secure American ports but also challenged British naval supremacy, significantly contributing to the ultimate success of the revolution.

The other scenarios do not accurately reflect France's involvement. They did not remain neutral; their active support marked a decisive shift in the war’s dynamics. They also did not support the British against the colonies, as their interests were aligned with helping America gain independence. Declaring war on the colonies would have been contrary to their alliance with the Americans. Therefore, the significant military support provided by France was pivotal in changing the course of the Revolutionary War.