What is the main conflict in A Bell for Adano by John Hersey?

A Bell for Adano is about a man named Major Victor Joppolo, who is positioned in Adano, Italy as World War II is coming to a close. He positively impacts all of the people of Adano and improves their lives there, despite inherent limitations within the government, and is eventually forced to leave the town due to an overbearing, stubborn and ignorant General.