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