This chapter would not be complete without some reference to the use of machine guns in enclosed country such as is found in the United Kingdom. Clery, in his _Minor Tactics_, p. 118, says that cultivated country is the most favourable to the attack, while in defence the country to the front cannot be too open. “In the first, infantry gains a succession of covered positions by means of which it comes on more equal terms with the defence. In the second, the infantry of the defence has a clear field to destroy the assailants as they approach.” Apart from civil war, the only possible occasion for the use of machine guns in the British Isles is against an invader, and it is well known to students of modern war that the prospects of a successful invasion do not depend upon the strength or weakness of our fleet, but on that of our army for home defence. The duty of a fleet in time of war is to go to sea and destroy the enemy’s ships, and while it is absent on this mission an opportunity for invasion may occur, the success of which will wholly depend upon the force the invader will meet on landing. The Japanese recently landed in Manchuria in spite of Russia’s superior naval strength; but because it was the case of an island invading a continent, we do not apply the lesson to ourselves, and are content to believe that a continent cannot invade an island. It is obvious to the military student that no invasion will be attempted unless its success is reasonably certain, and the presence of four divisions of regular troops at home renders such an enterprise extremely difficult, if not impossible, without permanent command of the sea. But these four divisions are not the Home Defence Force, and form that part of our Expeditionary Army for service outside the United Kingdom. We may, therefore, rest assured that as long as we retain command of the sea, no invasion can take place until we are involved in an over-seas war which requires a more or less large portion of our Expeditionary Force--an event which has happened almost every decade. It will be safe, therefore, to assume that in the event of an invasion we shall have to rely on our Territorial Army to meet the enemy, and it will be doing this force no injustice to assume that they will be compelled to act on the defensive in the face of a highly trained and disciplined Continental Army. Indeed, it is difficult for a soldier to realise how a Volunteer force, trained for fourteen days in the year and unacquainted with military discipline, can hope to meet on equal terms, even if superior by three to one in numbers, the pick of Continental manhood trained under an iron discipline for the minimum of two years.