SEA POWER. The term means, essentially, the influence which a nation can exert to secure its rights and uphold its interests on the seas and oceans of the world both in peace and in war. It also implies the ability to deny the free use of the sea to an enemy. A nation which possesses a sizeable navy is often referred to as a "sea Power." It should not be confused with the one time prevalent but generally misused expression "command of the sea," or with the still popular but often indef inite "freedom of the seas." It must also be regarded as being quite distinct from the old phrase "sovereignty of the sea," which had a very definite meaning.
"Command of. the sea," in a literal sense, has always been a vainglorious claim. From time to time one nation or another has secured such a predominating influence at sea that enemy ships could only venture forth with grave risk of capture or destruc tion, while even neutral shipping only plied its trade on suffer ance; but, even so, this influence varied both as regards its extent and its duration and in no case has it been so absolute in character that it justified the use of such a term as "command." To-day it is generally recognised that no nation has the right, nor is it practicable, to claim appropriation of the seas, as a whole, even in time of war. In time of peace the complete "freedom of the seas" is one of the unwritten canons of normal international relations; an essential condition for world wide security and all that civilisation stands for, and one which no Power would wish to challenge. In time of war, however, sea power comes into play as a force to preserve the "freedom of the seas" for friendly interests and to make them perilous for enemy interests.
This force may operate in a variety of ways, the chief of which may be summarised as follows. (I) It may safeguard friendly shipping from attack on the most frequented or impor tant sea routes. (2) It may deny the use of the sea to the enemy for the transport of armed forces and supplies which would enable him to invade friendly territory or carry on a campaign overseas. (3) It may deny the use of the sea to shipping which would directly or indirectly assist the enemy by conveying to him essential commodities for his people's exist ence as well as warlike materials in raw or manufactured form for his fighting forces. (4) It may enable a nation to exercise
complete control of local waters for the purpose of effecting a landing in enemy territory or of securing the approaches to friendly harbours or to a fleet base.
All these are practical forms which sea power has assumed in time of war. The right to exercise it in full has often been disputed, and efforts have been made, notably by the Declaration of Paris of 1856, and by the unratified Declaration of London of 1909, to safeguard the interests of neutrals on the seas. But the World War showed that, actually, it is exceedingly difficult, if not impossible, to make fine distinctions between articles which are contraband and those which are non-contraband and between the nominal and real ownership of shipping conveying the for mer, and between the ports and firms to which goods are ostensibly consigned and their real and final destinations. War on such a scale involves the entire rival nations and not merely their armed forces; this means that all commodities which sustain a nation's resistance, whether they be essentially warlike or merely of use for civil comfort, will come to be regarded as contraband. From this it follows that sea power may be directed to cutting off all possible channels of supply.
Nevertheless this does not mean that, today, there can be no International Law relating to war at sea, no Courts of Appeal for the ill-used ship owner and no Prize Courts to adjudicate on what are and what are not good and proper prizes. Such is not the case. While, in a life and death struggle, a desperate nation may defy all international codes, as Germany did in the conduct of her submarine campaign (q.v.) in the World War, yet, there can be little doubt that adherence to the spirit of international usages in the application of sea power, as in that of all other forceful methods, will, in the long run, prove the best course for a belligerent to follow.