In my chapter on "Invasion" no mention is made of those subsidiary forms of military enterprise across the sea which are known as raids. I have treated invasion as an enterprise having for its object the subjugation of the country invaded, or at least the subjection of its people and their rulers to the enemy's will. As such it requires a force commensurate in numbers with the object to be attained, and it stands to reason that this force must needs be so large that its chances of evading the vigilance of an enemy who is in effective command of the sea must always be infinitesimal. A raid, on the other hand, is an enterprise of much lesser magnitude and much smaller moment. Its method is to elude the enemy's naval guard at this or that point of his territory; and, having done so, its purpose is to land troops at some vulnerable point of the territory assailed, there to create alarm and confusion and to do as much harm as they can--which may be considerable before their sea communications are severed by the defending naval force assumed to be still in effective command of the sea affected. If that command is maintained, the troops engaged in the raid must inevitably be reduced sooner or later to the condition of a forlorn hope which has failed. If, on the other hand, that command is overthrown, then the troops aforesaid may prove to be the advanced guard of an invasion to follow. Thus, although a successful raid may sometimes be carried out in the teeth of an adverse command of the sea, yet it cannot be converted into an invasion until that adverse command has been assailed and overthrown. It is thus essentially fugitive in character, possibly very effective as a diversion, certain to be mortifying to the belligerent assailed, and not at all unlikely to cause him much injury and even more alarm, but quite incapable of deciding the larger issues of the conflict so long as his command of the sea remains unchallenged. It is perhaps expedient to say this much on the subject, because the programme of the Naval Manoeuvres of this year is known to have included a series of raids of this fugitive character. Whether, or to what extent, any of these operations were adjudged to have been successful I do not know. I am only concerned to point out that, whether successful or not, their utmost success can throw little or no light on the problem of invasion unless in the course of the same operations the defenders' command of the sea was adjudged to have been overthrown.