He constantly affirmed that it was in Italy alone that Rome was vulnerable, and that by striking hard and often there, she might be conquered. He did not despair of effecting the deliverance of the world by a conflict on their own shores, even after the battle of Zama had to all appearance decisively settled the conflict in favour of the Capitol, and nothing remained to combat the legions but the unwarlike soldiers of the Eastern monarch. His own campaigns demonstrate that he was right: the Gauls and the Carthaginians in different ages brought the Romans to the brink of ruin; but it was by victories on the Tiber that Brennus and Hannibal penetrated to their gates. Nor is it difficult to see to what cause this comparative weakness at home of so great a military power was owing. Rome was not merely a powerful state, but the head of a great military confederacy; the resources which, partly by force, partly by inclination, and the natural appetite of mankind for victory and plunder, were ranged on her side, were in great part derived from foreign states. When she carried the war into foreign states, this formidable mass of auxiliaries doubled the strength of her legions; when she was assailed at home, one half of them were lost, or appeared in the ranks of her enemies. The same cause appeared at a subsequent period in the campaigns of Napoleon: his armies were innumerable, his force irresistible, as long as he headed the forced confederacy of western Europe, and he invaded Russia with five hundred thousand men; but when the disaster of Moscow, and the resurrection of Germany, brought the Russians into France, the boasted strength of the empire disappeared, its allies passed over to the other side, and the mighty conqueror was reduced to a painful defensive with fifty thousand men on the plains of Champagne.