The emperor's ambitions began to take on a larger form. Under the auspices of the government, M. Lesseps commenced a transisthmian canal, which would open communication between the Mediterranean Sea and the Red Sea. Then, in 1862, a less peaceful scheme developed. An expedition was planned to Mexico, against which country France had a small grievance.
The United States was at this time fighting for its life in a civil war of gigantic proportions. The time was favorable for a plan conceived by the emperor to convert Mexico into an empire under a French protectorate. The principle known as the Monroe Doctrine forbade the establishment of any European power upon the Western hemisphere; but the United States was powerless at the moment to defend it, and by the time her hands were free, even if she were not disrupted, an Empire of Mexico would be established, and French troops could defend it.
In a few months the French army was in the city of Mexico, and an Austrian prince was proclaimed emperor of a Mexican empire.
This ill-conceived expedition came to a tragic and untimely end in 1867. The civil war ended triumphantly for the Union. Napoleon, realizing that, with her hands free, the United States would fight for the maintenance of the Monroe Doctrine, promptly withdrew the French army from Mexico, leaving the emperor to his fate. A republic was at once established, and the unfortunate Maximilian was ordered to be shot.
The finances of France and the prestige of the emperor had both suffered from this miserable attempt. At the same time, something had occurred which changed the entire European problem in a way most distasteful to Louis Napoleon. Prussia, in a seven weeks' war, had wrenched herself free from Austria (1866). Instead of a disrupted United States, which he had expected, there was a disrupted German Empire which he did not expect!
The triumph of Protestant Prussia was a triumph of liberalism. It meant a new political power, a rearrangement of the political problem in Europe, with Austria and despotism deposed. This was a distinct blow to the Emperor's policy, and to the headship in Europe which was its aim. Then, too, the Crimea, Magenta, and Solferino looked less brilliant since this transforming seven-weeks' war, behind which stood Bismarck with his wide-reaching plans.
His own magnificent scheme of a Hapsburg empire in Mexico under a French protectorate had failed, and now there had suddenly arisen, as if out of the ground, a new political Germany which rivalled France in strength. The thing to do was to recover his waning prestige by a victory over Prussia.
The Empress Eugénie, devoutly Catholic in her sympathies, saw, in the ascendancy of Protestant Prussia and the humiliation of Catholic Austria, an impious blow aimed at the Catholic faith in Europe. So, as the emperor wanted war, and the empress wanted it, it only remained to make France want it too; for war it was to be.
Only one obstacle existed: there was nothing to fight about! But that was overcome. In 1870 the heart of the people of France was fired by the news that the French Ambassador had been publicly insulted by the kindly old King William. There had been some diplomatic friction over the proposed occupancy of a vacant throne in Spain by a member of the Hohenzollern (Prussian) family.
Whether true or false, the rumor served the desired purpose. France was in a blaze of indignation, and war was declared.