To what extent was the American Revolution a European conflict?
The American Revolution was primarily a conflict between the American colonists and the British. However, the war did widen as many other European countries took the war as a chance to weaken the British.
The French are the best known for having participated in the war in the Americas. However, particularly late in the war, there were other countries involved in fighting in places other than North America. There were naval battles between the British and the Spaniards in the Caribbean and the Gulf of Mexico. There was fighting with France in India. There was even fighting between the British and the Netherlands.
Although the war was mainly about American independence, it also widened to include other countries that wanted to chip away at British dominance in Europe and elsewhere.