When this method of advance is used the machine guns working as independent sections should be used to hold important features, such as bridge-heads, defiles, passes, and villages in the line of observation. If positions are carefully selected whence effective fire can be brought to bear on points which the enemy must pass in close order, and the usual procedure as to cover, concealment, and range-taking is observed, the mounted troops may be spared much fatigue and given opportunities for resting men and horses. USE OF MACHINE GUNS IN A RETREAT During the battle the Protective Cavalry will be used in the way already described in the previous chapter, in which we also dealt with the Pursuit; we will therefore now see how they may be used to assist a Retreat. “When retreat appears inevitable the routes to the rallying position should never be so close to the battlefield as to come at once under the fire of the enemy. It should be occupied as soon as possible by some portion of the artillery, and by complete infantry units. _The cavalry and other mounted troops, aided by a strong force of artillery, will meanwhile check the enemy’s advance_, and the remainder of the force, with the exception, if possible, of a rear guard in support of the mounted troops, will move as rapidly as possible to the shelter of the rallying position and there reorganise. Steps should be taken immediately to secure any bridges, defiles, or other vital points on the line of retreat, at which the enemy’s mounted troops might intercept the force. Commanders of retreating troops must recognise that their greatest danger will arise from attacks in flank delivered by the enemy’s mounted troops and horse artillery; if possible, therefore, they should take precautions that _all ground commanding their line of retreat is occupied by flank guards_.”[14] The action of the Protective Cavalry is indicated in the first paragraph quoted in italics, while the second gives the only method by which a retreat can be rendered successful or secure. In no phase of modern war are machine guns so valuable as during a retreat, and it is quite probable that, properly organised and handled, they may make the pursuit so difficult and costly as to render the retreat a far less dangerous undertaking than it has been in the past. It is not difficult to realise that an arm possessing such great mobility, together with rapidity and concentration of fire, before which no closed bodies can exist at effective range, will be able not merely to check and delay pursuing cavalry, but may even prevent any effective pursuit by mounted men alone. The lack of machine guns on the side of the Russians in the late war renders this point still to be proved by a future campaign; but it is well known that the machine guns with the 1st Siberian Army Corps constantly checked the Japanese pursuit, and more than once rendered a flanking movement abortive.