There was an enormous disparity in numbers between the French army—or it would better be called Napoleon's army—and that of the allies he purposed to attack. The allies were to the French in the ratio of about two to one. Whatever else was lacking, Napoleon had not lost his audacity, nor when his intentions are disclosed by a study of his plans, can it be argued that his strategic intention was lacking in brilliancy or daring.
He determined with his smaller but compact and manageable army to thrust himself between the two wings of the somewhat loosely coherent enemy under its divided command; to hold off one while he smashed the other and then to concentrate upon the surviving half and mete out to it the same hard fortune. In other words, trusting to his ability, he deliberately placed his own army between two others, each of which practically equaled his own. He thrust himself within the jaws of a trap, to use a homely simile, intending to hold one arm of the trap open while he broke up the other. He intended to burst through the allied line and smash up each half in succession.
Of course there was always the danger that he could not burst through that line; or that he could not hold back one half while he fought the other, or that holding back one half he could not beat the other, or having beaten one half he would be too weak to fall on the other. There was always the danger that the trap would be sprung, that he would be caught in its jaws or, to change the metaphor, that he would be like the wheat between the upper and the nether millstone. Still he did not think so, and he did not go into the undertaking blindly. As he had said, in his own case, "War was not a conjectural art," and he had most carefully counted the cost, estimated the probabilities. In short, he looked well before he leaped—yet a man may look well and leap wrong after all.
On these considerations he based his grand strategy. The army of the Prussians had approached the French frontier from the east; the army of the English and allies from the northwest. Napoleon had a complete knowledge of one of the Captains opposing him. He knew and accurately estimated Blücher. He did not know and he did not accurately estimate Wellington. He viewed the latter with contempt; the former with a certain amount of disdainful approbation, for while Blücher was no strategist and less of a tactician, he was a fighter and a fighter is always dangerous and to be dreaded. Gneisenau, a much more accomplished soldier, was Blücher's second in command, but he was a negligible factor in the Emperor's mind. The fact that Wellington had beaten all of Napoleon's Marshals with whom he had come in contact had intensified the Emperor's hatred. Instead of begetting caution in dealing with him, Napoleon's antagonism had blinded him as to Wellington's ability.
He also rated the Prussians higher than the English as fighters, and when his officers, who had felt the power of the thin red line which had so often wrecked the French column, explained to him that there were no better defensive fighters on earth than the English, not even the Russians, he had laughed them to scorn, attributing their warnings to the fact that they had been beaten in Spain and had grown timid. The Emperor did not purpose to be beaten in France or Belgium by the stolid English.
In more detail his first plan was to confuse Wellington, who held the right of the allied line, then fall upon him before he had time to concentrate, and beat him or contain him with a detachment under Ney, while the Emperor in person thereafter put Blücher to rout—and all of these things he came very near accomplishing completely. Certainly, he carried out his plans successfully and to the letter until the final day of battle.
He reasoned that if he could beat Blücher and threaten his communications, what was left of the Prussian army, which Napoleon hoped would not be much, would immediately retreat eastward; and that when Blücher had been thrown out of the game for the present, he could turn on Wellington and his English and allies and make short work of him. It did not occur to him that even if he beat Blücher and beat Wellington, provided the defeats did not end in utter routs, and they both retreated, they might withdraw on parallel lines and effect a junction later when even after the double defeat they would still so greatly outnumber him that his chances of success would be faint indeed.
The possibility of their pursuing any other course than that he had forecast for them never entered his mind. His own conception of their action was, in fact, an obsession with him. Yet that which he thought they would do they did not; and that which he was confident they would not do they did!