Maximilian's assumption of the role of Emperor of Mexico irked many nerves.
The domestic opposition from the Republicans was one thing, but, since he had been installed by the French, many within the Constitutionalists also worried about the expanding influence of the French, choosing to wait and see.
Before Maximilian's arrival in Mexico, Lincoln had already made his stance clear, opposing French intervention in Mexican domestic affairs and condemning the French for violating the Monroe Doctrine.
These were minor issues; with the French even meddling in U.S. internal affairs, who would take the Monroe Doctrine to heart? The French simply ignored Lincoln's protests.
The Spaniards had already occupied Haiti Island, Austria had reached into the Central American region, and the British intended to retake the Western Region. Naturally, the French saw nothing wrong with plotting to take over Mexico.
