Some Principles of Maritime Strategy

by Julian Stafford Corbett

II. ATTACK AND DEFENCE OF TRADE

The base idea of the attack and defence of trade may be summed up in the old adage, "Where the carcase is, there will the eagles be gathered together." The most fertile areas always attracted the strongest attack, and therefore required the strongest defence; and between the fertile and the infertile areas it was possible to draw a line which for strategical purposes was definite and constant. The fertile areas were the terminals of departure and destination where trade tends to be crowded, and in a secondary degree the focal points where, owing to the conformation of the land, trade tends to converge. The infertile areas were the great routes which passed through the focal points and connected the terminal areas. Consequently attack on commerce tends to take one of two forms. It may be terminal or it may be pelagic, terminal attack being the more profitable, but demanding the greater force and risk, and pelagic attack being the more uncertain, but involving less force and risk.

These considerations lead us directly to the paradox which underlies the unbroken failure of our enemies to exercise decisive pressure upon us by operations against our trade. It is that where attack is most to be feared, there defence is easiest. A plan of war which has the destruction of trade for its primary object implies in the party using it an inferiority at sea. Had he superiority, his object would be to convert that superiority to a working command by battle or blockade. Except, therefore, in the rare cases where the opposed forces are equal, we must assume that the belligerent who makes commerce destruction his primary object will have to deal

with a superior fleet. Now, it is true that the difficulty of defending trade lies mainly in the extent of sea it covers. But, on the other hand, the areas in which it tends to congregate, and in which alone it is seriously vulnerable, are few and narrow, and can be easily occupied if we are in superior force. Beyond those areas effective occupation is impossible, but so also is effective attack. Hence the controlling fact of war on commerce, that facility of attack means facility of defence.

Beside this fundamental principle we must place another that is scarcely less important. Owing to the general common nature of sea communications, attack and defence of trade are so intimately connected that the one operation is almost indistinguishable from the other. Both ideas are satisfied by occupying the common communications. The strongest form of attack is the occupation of the enemy's terminals, and the establishment of a commercial blockade of the ports they contain. But as this operation usually requires the blockade of an adjacent naval port, it also constitutes, as a rule, a defensive disposition for our own trade, even when the enemy's terminal area does not overlap one of our own. In the occupation of focal areas the two ideas are even more inseparable, since most, if not all, such areas are on lines of communication that are common. It will suffice, therefore, to deal with the general aspect of the subject from the point of view of defence.

It was in conformity with the distinction between fertile and infertile areas that our old system of trade defence was developed. Broadly speaking, that system was to hold the terminals in strength, and in important cases the focal points as well. By means of a battle-squadron with a full complement of cruisers they were constituted defended areas, or "tracts" as the old term was, and the trade was regarded as safe when it entered them. The intervening trade-routes were left as a rule undefended. Thus our home terminals were held

by two battle-squadrons, the Western Squadron at the mouth of the Channel, and the North Sea or Eastern Squadron with its headquarters usually in the Downs. To these was added a cruiser squadron on the Irish station based at Cork, which was sometimes subordinate to the Western Squadron and sometimes an independent organisation. The area of the Western Squadron in the French wars extended, as we have seen, over the whole Bay of Biscay, with the double function, so far as commerce was concerned, of preventing the issue of raiding squadrons from the enemy's ports, and acting offensively against his Atlantic trade. That of the North Sea squadron extended to the mouth of the Baltic and the north-about passage. Its main function during the great naval coalitions against us was to check the operations of Dutch squadrons or to prevent the intrusion of French ones north-about against our Baltic trade. Like the Western Squadron, it threw out divisions usually located at Yarmouth and Leith for the protection of our coastwise trade from privateers and sporadic cruisers acting from ports within the defended area. Similarly, between the Downs and the Western Squadron was usually one or more smaller squadrons, mainly cruisers, and generally located about Havre and the Channel Islands, which served the same purpose for the Norman and North Breton ports. To complete the system there were flotilla patrols acting under the port admirals and doing their best to police the routes of the coastwise and local traffic, which then had an importance long since lost. The home system of course differed at different times, but it was always on these general lines. The naval defence was supplemented by defended ports of refuge, the principal ones being on the coast of Ireland to shelter the ocean trade, but others in great numbers were provided within the defended areas against the operations of privateers, and the ruins of batteries all round the British shores testify how complete was the organisation.

A similar system prevailed in the colonial areas, but there

the naval defence consisted normally of cruiser squadrons stiffened with one or two ships-of-the-line mainly for the purpose of carrying the flag. They were only occupied by battle-squadrons when the enemy threatened operations with a similar force. The minor or interior defence against local privateers was to a large extent local; that is, the great part of the flotilla was furnished by sloops built or hired on the spot, as being best adapted for the service.

Focal points were not then so numerous as they have become since the development of the Far Eastern trade. The most important of them, the Straits of Gibraltar, was treated as a defended area. From the point of view of commerce-protection it was held by the Mediterranean squadron. By keeping watch on Toulon that squadron covered not only the Straits, but also the focal points within the sea. It too had its extended divisions, sometimes as many as four, one about the approaches to Leghorn, one in the Adriatic, a third at Malta, and the fourth at Gibraltar. In cases of war with Spain the latter was very strong, so as to secure the focal area against Cartagena and Cadiz. On one occasion indeed, in 1804-5, as we have seen, it was constituted for a short time an independent area with a special squadron. But in any case the Gibraltar area had its own internal flotilla guard under the direction of the port admiral as a defence against local privateers and pirates.