3. ELEMENTS OF SEA POWER[16] The first and most obvious light in which the sea presents itself from the political and social point of view is that of a great highway; or better, perhaps, of a wide common, over which men may pass in all directions, but on which some well-worn paths show that controlling reasons have led them to choose certain lines of travel rather than others. These lines of travel are called trade routes; and the reasons which have determined them are to be sought in the history of the world. Notwithstanding all the familiar and unfamiliar dangers of the sea, both travel and traffic by water have always been easier and cheaper than by land. The commercial greatness of Holland was due not only to her shipping at sea, but also to the numerous tranquil water-ways which gave such cheap and easy access to her own interior and to that of Germany. This advantage of carriage by water over that by land was yet more marked in a period when roads were few and very bad, wars frequent and society unsettled, as was the case two hundred years ago. Sea traffic then went in peril of robbers, but was nevertheless safer and quicker than that by land. A Dutch writer of that time, estimating the chances of his country in a war with England, notices among other things that the water-ways of England failed to penetrate the country sufficiently; therefore, the roads being bad, goods from one part of the kingdom to the other must go by sea, and be exposed to capture by the way. As regards purely internal trade, this danger has generally disappeared at the present day. In most civilized countries, now, the destruction or disappearance of the coasting-trade would only be an inconvenience, although water transit is still the cheaper. Nevertheless, as late as the wars of the French Republic and the First Empire, those who are familiar with the history of the period, and the light naval literature that has grown up around it, know how constant is the mention of convoys stealing from point to point along the French coast, although the sea swarmed with English cruisers and there were good inland roads. Under modern conditions, however, home trade is but a part of the business of a country bordering on the sea. Foreign necessaries or luxuries must be brought to its ports, either in its own or in foreign ships, which will return, bearing in exchange the products of the country, whether they be the fruits of the earth or the works of men’s hands; and it is the wish of every nation that this shipping business should be done by its own vessels. The ships that thus sail to and fro must have secure ports to which to return, and must, as far as possible, be followed by the protection of their country throughout the voyage.