The command of the sea does not mean immunity from the risks of naval warfare or from loss by the capture or sinking of merchant vessels. It does not imply absolute security for British coasts, for British coasts have been raided in every great war that Britain has waged. It does not even involve the defeat or destruction of the enemy's naval forces, or it would be a simple task for any naval Power to deprive us of the command of the sea by locking its fleets in harbour, and on that theory the forts of the Dardanelles would have enabled Turkey to deny the command of the sea to the combined fleets of the world. The meaning is familiar enough to intelligent students of history. Bacon sketched it three hundred years ago when he wrote, "He that commands the sea is at great liberty and may take as much and as little of the war as he will ... and the wealth of both Indies seems in great part but an accessory to the command of the seas." "Both Indies" have grown to-day to include the resources of nearly the whole extra-European world which the command of the sea placed at the disposal of the Entente and denied to the Central Empires; and the last great war, like those against Napoleon, Louis XIV, and Philip II, was decided by the same indispensable factor in world-power. Others might control for a time a continent; only those who command the sea can dispose of the destinies of the world. But while an essential factor in world-power, the command of the sea is not its sum; and the war throughout its course illustrated the weakness of attack by sea against a well-defended coast. No attempt was made to land an army on German territory, and complete command of the Ægean did not avail for the capture of Gallipoli. It could not turn sea into land nor enable a navy to do an army's work, and command of the sea while a more extensive is a less intensive kind of power than command of the land. The nature of the command varies, indeed, with the solidity of the element in which it is exercised: land is more solid than water, and water than air; the command of the land is therefore more complete than command of the sea, and command of the sea than command of the air; and endless confusion arose from the use of the same word to describe three different degrees of control. Victory can be achieved on sea, conquest only on land; and nothing like victory, let alone conquest, in war has yet been won in the air. Conquest, however, while it cannot be effected, can be prevented on sea, as it was at Salamis in 1588, at Trafalgar, and Navarino; for sea-power, while conclusive for defence, is merely conducive to offence, and that is why it has ever been a means of liberty rather than of despotism. Armies are the weapons of autocracy, navies those of freedom; for peoples do not live upon water, and only armies command their homes. Command of the sea is a sufficient protection for an island-empire; to conquer others it needs a superior army, and the