they hoped for something in exchange
France
The American victory at the Battle of Saratoga convinced France to become an ally of the United States.
The British wanted America to be under its power and they were willing to fight for it.
The enemy of my enemy is my friend. France had been beaten by the British in the French and Indian War. They were willing to help Americans to embarrass the British.
The British Parliament was not willing to support a new military campaign.
Because they knew the colonists had a good chance of winning and wanted revenge on the British.
They saw it as an inexpensive way to weaken the power of the British Empire and advance their own interests and empires.
France joined the Revolutionary War because they heard of the victories at Saratoga. Later Spain joined because they were allies with France.
There were strong hostilities between the French and the British
There were strong hostilities between the French and the British
There were strong hostilities between the French and the British
Americans were willing to fight for the right to govern themselves