The French Alliance: An International Revolution

American independence was won with foreign help, which links it directly to the crisis of the French monarchy. After the American victory at Saratoga in October 1777, France signed a treaty of alliance in February 1778, and Spain joined the war against Britain in 1779 as France's ally. French loans, weapons, troops and above all naval power proved decisive: at Yorktown in October 1781, French soldiers and the French fleet were essential to trapping the British army.

This shows a pattern: revolutions often depend on international rivalries. Yet French help came at a heavy cost, adding to the royal debt that brought on the crisis of 1789. Officers such as the Marquis de Lafayette returned home with republican ideas. Comparison with Latin America is useful: Spanish American patriots also sought foreign help, but Britain gave mostly unofficial support rather than an open alliance.