The transformation of society of which the French Revolution was the most striking symptom produced a corresponding change in the character of war.

By the Revolution the French people constituted itself the State, and the process was accompanied by so much passion and so much violence that it shortly involved the reconstituted nation in a quarrel with its neighbours the Germanic Empire and Prussia, which rapidly developed into a war between France and almost all the rest of Europe. The Revolution weakened and demoralised the French army and disorganised the navy, which it deprived of almost all its experienced officers. When the war began the regular army was supplemented by a great levy of volunteers. The mixed force thus formed, in spite of early successes, was unable to stand against the well-disciplined armies of Austria and Prussia, and as the war continued, while the French troops gained solidity and experience, their numbers had to be increased by a levy en masse or a compulsory drafting of all the men of a certain age into the army. In this way the army and the nation were identified as they had never been in modern Europe before, and in the fifth year of the war a leader was found in the person of General Bonaparte, who had imbued himself with the principles of the art of war, as they had been expounded by the best strategists of the old French army, and who had thus thought out with unprecedented lucidity the method of conducting campaigns. His mastery of the art of generalship was revealed by his success in 1796, and as the conflict with Europe continued, he became the leader and eventually the master of France. Under his impulse and guidance the French army, superior to them in numbers, organisation, and tactical skill, crushed one after another the more old-fashioned and smaller armies of the great continental Powers, with the result that the defeated armies, under the influence of national resentment after disaster, attempted to reorganise themselves upon the French model. The new Austrian army undertook its revenge too soon and was defeated in 1809; but the Prussian endeavour continued and bore fruit, after the French disasters in Russia of 1812, in the national rising in which Prussia, supported by Russia and Austria and assisted by the British operations in the Peninsula, overthrew the French Empire in 1814.

After the definitive peace, deferred by the hundred days, but finally forced upon France on the field of Waterloo, the Prussian Government continued to foster the school of war which it had founded in the period of humiliation. Prussian officers trained in that school tried to learn the lessons of the long period of war which they had passed through. What they discovered was that war between nations, as distinct from war between dynasties or royal houses, was a struggle for existence in which each adversary risked everything and in which success was to be expected only from the complete prostration of the enemy. In the long run, they said to themselves, the only defence consists in striking your adversary to the ground. That being the case, a nation must go into war, if war should become inevitable, with the maximum force which it can possibly produce, represented by its whole manhood of military age, thoroughly trained, organised, and equipped. The Prussian Government adhered to these ideas, to which full effect was given in 1866, when the Prussian army, reorganised in 1860, crushed in ten days the army of Austria, and in 1870 when, in a month from the first shot fired, it defeated one half of the French army at Gravelotte and captured the other half at Sedan. These events proved to all continental nations the necessity of adopting the system of the nation in arms and giving to their whole male population, up to the limits of possibility, the training and the organisation necessary for success in war.

The principle that war is a struggle for existence, and that the only effective defence consists in the destruction of the adversary's force, received during the age of Napoleon an even more absolute demonstration at sea than was possible on land. Great Britain, whether she would or no, was drawn into the European conflict. The neglect of the army and of the art of war into which, during the eighteenth century, her Governments had for the most part fallen, made it impracticable for her to take the decisive part which she had played in the days of William III. and of Marlborough in the struggle against the French army; her contributions to the land war were for the most part misdirected and futile. Her expeditions to Dunkirk, to Holland, and to Hanover embarrassed rather than materially assisted the cause of her allies. But her navy, favourably handicapped by the breakdown, due to the Revolution, of the French navy, eventually produced in the person of Nelson a leader who, like Napoleon, had made it the business of his life to understand the art of war. His victories, like Napoleon's, were decisive, and when he fell at Trafalgar the navies of continental Europe, which one after another had been pressed into the service of France, had all been destroyed.

Then were revealed the prodigious consequences of complete victory at sea, which were more immediate, more decisive, more far-reaching, more irrevocable than on land. The sea became during the continuance of the war the territory of Great Britain, the open highway along which her ships could pass, while it was closed to the ships of her adversaries. Across that secure sea a small army was sent to Spain to assist the national and heroic, though miserably organised, resistance made by the Spanish people against the French attempt at conquest. The British Government had at last found the right direction for such military force as it possessed. Sir John Moore's army brought Napoleon with a great force into the field, but it was able to retire to its own territory, the sea. The army under Wellington, handled with splendid judgment, had to wait long for its opportunity, which came when Napoleon with the Grand Army had plunged into the vast expanse of Russia. Wellington, marching from victory to victory, was then able to produce upon the general course of the war an effect out of all proportion to the strength of the force which he commanded or of that which directly opposed him.

While France was engaged in her great continental struggle England was reaping, all over the world, the fruits of her naval victories. Of the colonies of her enemies she took as many as she wanted, though at the peace she returned most of them to their former owners. Of the world's trade she obtained something like a monopoly. The nineteenth century saw the British colonies grow up into so many nations and the British administration of India become a great empire. These developments are now seen to have been possible only through the security due to the fact that Great Britain, during the first half of the nineteenth century, had the only navy worth considering in the world, and that during the second half its strength greatly preponderated over that of any of the new navies which had been built or were building. No wonder that when in 1888 the American observer, Captain Mahan, published his volume "The Influence of Sea Power upon History," other nations besides the British read from that book the lesson that victory at sea carried with it a prosperity, an influence, and a greatness obtainable by no other means. It was natural for Englishmen to draw the moral which was slumbering in the national consciousness that England's independence, her empire, and her greatness depended upon her sea power. But it was equally natural that other nations should draw a different moral and should ask themselves why this tremendous prize, the primacy of nations and the first place in the world, should for ever belong to the inhabitants of a small island, a mere appendage to the continent of Europe.

This question we must try to answer. But before entering upon that inquiry I will ask the reader to note the great lesson of the age of Napoleon and of Nelson. It produced a change in the character of war, which enlarged itself from a mere dispute between Governments and became a struggle between nations. The instrument used was no longer a small standing army, but the able-bodied male population in arms. Great Britain indeed still retained her standing army, but for the time she threw her resources without stint into her navy and its success was decisive.