But the cool judgement and firm temper which distinguished Wellington enabled him to face a responsibility from which weaker men would have shrunk. "I conceive," he answered, "that the honour and interest of our country require that we should hold our ground here as long as possible; and, please God, I will maintain it as long as I can." By the addition of Portuguese troops who had been trained under British officers, his army was now raised to fifty thousand men; and though his inferiority in force compelled him to look on while Massena reduced the frontier fortresses of Ciudad Rodrigo and Almeida, he inflicted on him a heavy check at the heights of Busaco, and finally fell back in October 1810 on three lines of defence which he had secretly constructed at Torres Vedras, along a chain of mountain, heights crowned with redoubts and bristling with cannon. The position was impregnable: and able and stubborn as Massena was he found himself forced after a month's fruitless efforts to fall back in a masterly retreat; but so terrible were the privations of the French army in passing again through the wasted country that it was only with forty thousand men that he reached Ciudad Rodrigo in the spring of 1811. Reinforced by fresh troops, Massena turned fiercely to the relief of Almeida, which Wellington had besieged. Two days' bloody and obstinate fighting however, in May 1811, failed to drive the English army from its position at Fuentes d'Onore, and the Marshal fell back on Salamanca and relinquished his effort to drive Wellington from Portugal. But great as was the effect of Torres Vedras in restoring the spirit of the English people, and in reviving throughout Europe the hope of resistance to the tyranny of Napoleon, its immediate result was little save the deliverance of Portugal. If Massena had failed, his colleagues had succeeded in their enterprises; the French were now masters of all Spain save Cadiz and the eastern provinces, and even the east coast was reduced in 1811 by the vigour of General Suchet.
While England thus failed to rescue Spain from the aggression of Napoleon, she was suddenly brought face to face with the result of her own aggression in America. The repeal of the Non-Intercourse Act in 1810 had in effect been a triumph for Britain: but the triumph forced Napoleon's hand. As yet all he had done by his attack on neutral rights had been to drive the United States practically to join England against him. To revenge himself by war with them would only play England's game yet more; and with characteristic rapidity Napoleon passed from hostility to friendship. He seized on the offer with which America had closed her efforts against the two combatants, and after promising to revoke his Berlin and Milan Decrees he called on America to redeem her pledge. In February 1811, therefore, the United States announced that all intercourse with Great Britain and her dependencies was at an end. The effect of this step was seen in a reduction of English exports during this year by a third of their whole amount. It was in vain that Britain pleaded that the Emperor's promises remained unfulfilled, that neither of the decrees was withdrawn, that Napoleon had failed to return the American merchandise seized under them, and that the enforcement of non-intercourse with England was thus an unjust act, and an act of hostility. The pressure of the American policy, as well as news of the warlike temper which had at last grown up in the United States, made submission inevitable; for the industrial state of England was now so critical that to expose it to fresh shocks was to court the very ruin which Napoleon had planned.