The American Government agrees that for a blockade the cordon of ships in the offing is no longer practicable in the face of an enemy ‘possessing the means and opportunity to make an effective defence by the use of submarines, mines, and aircraft,’ and is therefore no longer to be insisted on. It believes that a ‘long-distance blockade’ is now inevitable. The importance of this admission cannot be exaggerated. It might, I should have thought, be contended that a ‘blockade’ cannot be effective if the enemy possesses sufficient means of offence--in other words, has the present means of destroying its effectiveness. It can never be sufficiently insisted on that ‘blockade’ has, in addition to its realities, a technical and highly artificial side. Under the conditions of warfare existing at the time the rules were evolved, the visible sign of its effectiveness was the presence of the blockading ships in the offing; that was the fact from which the danger to merchant ships trying to run in to the blockaded coast became evident. But if, whether by submarines, mines, or aircraft, this danger ceases to be evident, if it can be actually eliminated, if by the offensive protection of destroyers or cruisers there is an evident danger to the blockading squadron, it would seem to follow that both the real and the artificial effectiveness of that squadron would be destroyed. A blockade liable to be seriously questioned, the blockading ships to be annihilated, by an opposing squadron, seems to involve a contradiction in terms.[37] But all this is top-hamper of curious argument, and must go by the board when modern fleets take up their war-stations. The enforcement of a ‘long-distance blockade’ is recognised by the American Protest as being one of their modern duties. But for what purpose? For that extreme exhibition of force which the command of the sea enables one of the belligerents to display in order to strangle the life out of the enemy. That is the principle of blockade--the exercise of sea-power to stop _all_ supplies from going to the enemy, because he has that power; and the Protest admits that this power may now be exercised in a wider area than in days gone by: exercised against the enemy, and therefore exercised against the neutral merchant, whose chances of getting even those things to the enemy which had, before its exercise, been allowed to pass as non-contraband are correspondingly diminished. Let it be noted at once in italics that this admission comes from a Government which is the most powerful protester against infringements of what it holds to be the rights of neutral merchants.