If only France joined, the war could have dragged on much longer. France gave the Patriots most of their guns, gunpowder, and money. The French Navy was crucial at the Battle of Yorktown in 1781. They trapped the British army by blocking their escape by sea. However, fighting a global war against Britain alone would have bankrupted France and left American troops starving.

If only Spain helped, the Americans would have lost. Spain never made a formal alliance with the 13 colonies. They secretly sent money and weapons, and they fought Britain on a second front in Florida and the Gulf of Mexico. Without the French Navy at Yorktown, the British fleet would have easily destroyed the Patriot troops.

How both superpowers worked together: France and Spain fought Britain all over the world. Britain had the best navy in the world. Britain had to send many warships to Europe to protect their home islands from Franco-Spanish invasion fleets. Britain also had to protect their valuable colonies in the Caribbean. This forced Britain to split its troops and ships. Spain also paid for the war. At the very end of the war, Spanish envoy Francisco de Saavedra raised the silver needed to pay General George Washington's troops. This meant the Patriots could march to Virginia to win the war. Both countries were needed to stretch Britain to its breaking point.