Maximillian offers Juárez the position of prime minister, but Juárez's refusal to compromise democratic self-rule for the Mexican people creates an unbridgeable rift between the two. When the American Civil War comes to an end, the United States warns Napoleon that it intends to enforce the Monroe Doctrine by military force if necessary, sending arms in support of Juárez's army. Their efforts are thwarted by Vice President Alejandro Uradi (Joseph Calleia), who seizes the American ammunition and therefore virtually guarantees victory for Maximilian. However, Napoleon orders all French troops to evacuate Mexico, leaving Maximilian without an army.