Sutra 16
यदा वा पश्येत्मित्रमाक्रन्दश्च मे शूरवृद्धानुरक्तप्रकृतिः विपरीतप्रकृतिः परः पार्ष्णिग्राहश्चासारश्च शक्ष्यामि मित्रेणासारमाक्रन्देन पार्ष्णिग्राहं वा विगृह्य यातुमिति तदा विगृह्य यायात् ॥ कZ_०७.४.१६ ॥
yadā vā paśyet mitram ākrandaś ca me śūravṛddhānuraktaprakṛtiḥ viparītaprakṛtiḥ paraḥ pārṣṇigrāhaś cāsāraś ca śakṣyāmi mitreṇāsāram ākrandena pārṣṇigrāhaṃ vā vigṛhya yātum iti tadā vigṛhya yāyāt
Or, when he sees that his ally and his supporting rear state are loyal and composed of brave and experienced constituents, while the enemy’s constituents are adverse; and when the enemy’s ‘heel-grasper’ (rear-threatening neighbor) and his weak ally are vulnerable—so that with his ally he can strike the enemy’s weak ally, or with his rear-support he can strike the heel-grasper—then he should initiate hostilities and march.
FAQs
March when your support system (ally + rear base) is reliable, and the enemy’s support system (weak ally + rear threat) can be neutralized through coordinated action.
Because an expedition fails if the rear is threatened; neutralizing or containing the heel-grasper is a prerequisite to sustained operations.