The armies required for the proposed imperial victory

The initial estimate is roughly 100,000 French troops and at least as many Mexican troops, preferably 200,000 or more Mexicans. The political argument then requires the Mexican contribution to exceed the French contingent. French forces would secure important positions while Mexican formations carried much of the fighting. Overwhelming strength is intended to prevent a prolonged struggle against a perceived colonial occupier. A Mexican contribution no larger than the French contingent would leave Maximilian dependent on France and undermine his claim to political independence. These figures describe the counterfactual requirement rather than the historical expedition.