The geographical position of a country may not only favor the concentration of its forces, but give the further strategic advantage of a central position and a good base for hostile operations against its probable enemies. This again is the case with England; on the one hand she faces Holland and the northern powers, on the other France and the Atlantic. When threatened with a coalition between France and the naval powers of the North Sea and the Baltic, as she at times was, her fleets in the Downs and in the Channel, and even that off Brest, occupied interior positions, and thus were readily able to interpose their united force against either one of the enemies which should seek to pass through the Channel to effect a junction with its ally. On either side, also, Nature gave her better ports and a safer coast to approach. Formerly this was a very serious element in the passage through the Channel but of late, steam and the improvement of her harbors have lessened the disadvantage under which France once labored. In the days of sailing-ships, the English fleet operated against Brest making its base at Torbay and Plymouth. The plan was simply this: in easterly or moderate weather the blockading fleet kept its position without difficulty but in westerly gales, when too severe, they bore up for English ports, knowing that the French fleet could not get out till the wind shifted, which equally served to bring them back to their station.
The advantage of geographical nearness to an enemy, or to the object of attack, is nowhere more apparent than in that form of warfare which has lately received the name of commerce-destroying, which the French call guerre_de course. This operation of war, being directed against peaceful merchant vessels which are usually defenceless, calls for ships of small military force. Such ships, having little power to defend themselves, need a refuge or point of support near at hand; which will be found either in certain parts of the sea controlled by the fighting ships of their country, or in friendly harbors. The latter give the strongest support, because they are always in the same place, and the approaches to them are more familiar to the commerce-destroyer than to his enemy. The nearness of France to England has thus greatly facilitated her guerre_de course directed against the latter. Having ports on the North Sea, on the Channel, and on the Atlantic, her cruisers started from points near the focus of English trade, both coming and going. The distance of these ports from each other, disadvantageous for regular military combinations, is an advantage for this irregular secondary operation; for the essence of the one is concentration of effort, whereas for commerce-destroying diffusion of effort is the rule. Commerce-destroyers scatter, that they may see and seize more prey. These truths receive illustration from the history of the great French privateers, whose bases and scenes of action were largely on the Channel and North Sea, or else were found in distant colonial regions, where islands like Guadaloupe and Martinique afforded similar near refuge. The necessity of renewing coal makes the cruiser of the present day even more dependent than of old on his port. Public opinion in the United States has great faith in war directed against an enemy's commerce but it must be remembered that the Republic has no ports very near the great centres of trade abroad. Her geographical position is therefore singularly disadvantageous for carrying on successful commerce-destroying, unless she find bases in the ports of an ally.
If, in addition to facility for offence, Nature has so placed a country that it has easy access to the high sea itself, while at the same time it controls one of the great thoroughfares or the world's traffic, it is evident that the strategic value of its position is very high. Such again is, and to a greater degree was, the position of England. The trade of Holland, Sweden, Russia, Denmark, and that which went up the great rivers to the interior of Germany, had to pass through the Channel close by her doors; for sailing-ships hugged the English coast. This northern trade had, moreover, a peculiar bearing upon sea power for naval stores, as they are commonly called, were mainly drawn from the Baltic countries.
But for the loss of Gibraltar, the position of Spain would have been closely analogous to that of England. Looking at once upon the Atlantic and the Mediterranean, with Cadiz on the one side and Cartagena on the other, the trade to the Levant must have passed under her hands, and that round the Cape of Good Hope not far from her doors. But Gibraltar not only deprived her of the control of the Straits, it also imposed an obstacle to the easy junction of the two divisions of her fleet.