Complex sentence: The French fought a bitter 7 year war (the First Indochina War) to hold on to Indochina; it was largely funded by the United States and grew increasingly unpopular, especially after the stunning defeat at the Battle of Dien Bien Phu.
Split into simpler sentences: The French fought a bitter seven year war (the First Indochina War) to hold on to Indochina. It was largely funded by the United States and grew increasingly unpopular, especially after the stunning defeat at the Battle of Dien Bien Phu.