Two lines of operation having been decided on, the invading army is gathered at a point as close as possible to the coast to be invaded; that is, where the intervening sea is narrowest, and where the army’s passage will be exposed to interference for the shortest time.  The covering fleet will operate from a point as distant as convenient, so as to entice the enemy as far as possible from the army’s line of passage.  The defender replies by blockading the army’s ports of departure with a flotilla of light vessels capable of dealing with transports, or by establishing a mobile defence of the threatened coasts which transports cannot break unaided, or more probably he will combine both expedients.  The first fallacy of the invasion plan is then apparent.  The narrower the sea, the easier it is to watch.  Pure evasion becomes impossible, and it is necessary to give the transports sufficient armed strength by escort or otherwise to protect them against flotilla attack.  The defender at once stiffens his flotilla defence with cruisers and intermediate ships, and the invader has to arrange for breaking the barrier with a battle-squadron.  So weak and disturbing a position is then set up that the whole scheme begins to give way, if, that is, the defender has clung stubbornly to the strategy we always used.  Our battle-fleet refused to seek out that of the invader.  It has always held a position between the invader’s fleet and the blockaded invasion base, covering the blockade and flotilla defence.  To enable a battle-squadron to break our hold and to reinforce the army escort, the invader must either force this covering position by battle, or disturb it so effectively as to permit the reinforcing squadron to evade it.  But since ex hypothesi he is trying to invade without securing the command by battle, he will first try to reinforce his transport escort by evasion.  At once he is faced with new difficulty.  The reinforcement entails dividing his fleet, and this is an expedient so vicious and disturbing to morale, that no invader has ever been found to risk it.  And for this reason.  To make evasion possible for the detached squadron, he must bring up the rest of his force and engage the attention of the enemy’s fleet, and thus unless he is in very great superiority, and by hypothesis is not—­he runs the hazard of having his two divisions beaten in detail.  This method has sometimes been urged by Governments, but so loud have been the protests both from the fleet and the army, that it has always been dropped, and the invader finds himself at the end of the vicious circle.  Unable to reinforce his transport escort sufficiently without dividing his battle-fleet, he is forced to bring his whole force up to the army or abandon the attempt till command shall have been secured by battle.