The Maximilian Affair (1864-1867) was the diplomatic crisis resulting from French Emperor Napoleon III placing Austrian Archduke Maximilian on the throne of Mexico. Despite this violation of the Monroe Doctrine, the United States could not respond militarily due to the ongoing Civil War. Instead the United States refused to recognize the new government and demanded the removal of the French armies which propped it up. In 1866 French troops were removed after the United States positioned military forces along the Rio Grande. Ultimately, the crisis was resolved when Benito Juárez deposed and executed Maximilian in 1867.