Mbh 15.7.1a

"'Dhritarashtra said, "O best of kings, thou shouldst also reflect properly on war and peace. Each is of two kinds. The means are various, and the circumstances also, under which war or peace may be made, are various, O Yudhishthira.[18] O thou of Kuru's race, thou shouldst, with coolness, reflect on the two (viz., thy strength and weakness) with regard to thyself. Thou shouldst not suddenly march against a foe that is possessed of contented and healthy soldiers, and that is endued with intelligence. On the other hand, thou shouldst think carefully of the means of vanquishing him.[19] Thou shouldst march against a foe that is not provided with contented and healthy combatants. When everything is favourable, the foe may be beaten. After that, however, the victor should retire (and stay in a strong position). He should next cause the foe to be plunged into various calamities, and sow dissensions among his allies. He should afflict the foe and inspire terror in his heart, and attacking him weaken his forces. The king, conversant with the scriptures that marches against a foe, should think of the three kinds of strength, and, indeed, reflect on his own strength and of his foe.[20] Only that king, O Bharata, who is endued with alacrity, discipline, and strength of counsels, should march against a foe. When his position is otherwise, he should avoid defensive operations.[21] The king should provide himself with power of wealth, power of allies, power of foresters, power of paid soldiery, and power of the mechanical and trading classes, O puissant one.[22] Among all these, power of allies and power of wealth are superior to the rest. The power of classes and that of the standing army are equal. The power of spies is regarded by the king as equal in efficacy to either of the above, on many occasions, when the time comes for applying each. Calamity, O king, as it overtakes rulers should be regarded as of many forms.