to come out across very narrow fronts.  A fence of mines less than three hundred miles long and two hundred feet deep would, for example, completely bar their exit through the North Sea.  The U-boats run the gauntlet of that long narrow sea and pay a heavy toll to it.  If only our Admiralty would tell the German public what that toll is now, there would come a time when German seamen would no longer consent to go down in them.  Consider, however, what a submarine campaign would be for Great Britain if instead of struggling through this bottle-neck it were conducted from the coast of Norway, where these pests might harbour in a hundred fiords.  Consider too what this weapon may be in twenty years’ time in the hands of a country in the position of the United States.  Great Britain, if she is not altogether mad, will cease to be an island as soon as possible after the war, by piercing the Channel Tunnel—­how different our transport problem would be if we had that now!—­but such countries as Australia, New Zealand, and Japan, directly they are involved in the future in a war against any efficient naval power with an unimpeded sea access, will be isolated forthwith.  I cannot conceive that any of the great ocean powers will rest content until such a tremendous possibility of blockade as the submarine has created is securely vested in the hands of a common league beyond any power of sudden abuse.

It must always be remembered that this war is a mechanical war conducted by men whose discipline renders them uninventive, who know little or nothing of mechanism, who are for the most part struggling blindly to get things back to the conditions for which they were trained, to Napoleonic conditions, with infantry and cavalry and comparatively light guns, the so-called “war of manoeuvres.”  It is like a man engaged in a desperate duel who keeps on trying to make it a game of cricket.  Most of these soldiers detest every sort of mechanical device; the tanks, for example, which, used with imagination, might have given the British and French overwhelming victory on the western front, were subordinated to the usual cavalry “break through” idea.  I am not making any particular complaint against the British and French generals in saying this.  It is what must happen to any country which entrusts its welfare to soldiers.  A soldier has to be a severely disciplined man, and a severely disciplined man cannot be a versatile man, and on the whole the British army has been as receptive to novelties as any.  The German generals have done no better; indeed, they have not done so well as the generals of the Allies in this respect.  But after the war, if the world does not organize rapidly for peace, then as resources accumulate a little, the mechanical genius will get to work on the possibilities of these ideas that have merely been sketched out in this war.  We shall get big land ironclads which will smash towns.  We shall get air offensives—­let the experienced London reader think of an air raid going on hour after