Answer: To get revenge for recent French losses in North America.
The Seven Years War was fought in Europe from 1756-63. That conflict as it extended to colonial territories in the New World was known as the French and Indian War. Losing that conflict in North America to the British didn’t sit well with France. And so when the colonial Americans broke out in revolution against the British monarchy, France devoted enormous financial aid (as well as officer support) to the Americans. The cost to France for supporting America’s revolution added up to 1 billion livres (about 4 billion in today’s dollars). This is part of what put France’s debt problem over the edge and led to the French Revolution.
