Protection of the Army mentions in the Chapter II of book X in Arthashastra, that while marching through various ups and downs of the area, the army must be protected through the roughness faced due to harsh weather. It needs protection when it passes through vast dessert areas with no grasslands, and forests with difficult topography. In such conditions the conqueror should be watchful about the needs of his army.

Protection of the Army further entails that the conqueror should protect his army when it has to pass a long desert without water; when it is without grass, firewood and water; when it has to traverse a difficult road; when it is harassed by an enemy's attacks ; when it is suffering from hunger and thirst after a journey; when it is ascending or descending a mountainous country full of mire, water-fools, rivers and cataracts; when it finds itself crowded in a narrow and difficult path; when it is halting, starting or eating; when it is tired from a long march; when it is sleepy; when it is suffering from a disease, pestilence of famine; when a great portion of its infantry, cavalry and elephants is diseased; when it is not sufficiently strong; or when it is under troubles. He should destroy the enemy's army under such circumstances.

Protection of the Army further claims that when the enemy's army is marching through a path traversable by a single man, the commander (of the invade, army) should ascertain its strength by estimating the quantity of foodstuffs, grass, bedding, and other requisites' fire pots (agninidhana), flags and weapons. He should also conceal those of his own army. Keeping a mountainous or river fortress with all its resources at his back in his own country, he should fight or put up his camp.

Thus, the Protection of the Army is the second important work of the conqueror who shall not only defeat his enemy but protect his own people.