Kautilya's Arthashastra 5.6.22

5.6.22

pareṇābhiyukto vā yathoktam āpatpratīkāraṃ kuryāt //

In case of the king's demise in an enemy's land, the minister, having brought about an agreement between the enemy and a friend pretending to be an enemy of the dead king, may withdraw himself; or having installed in the king's fort any one of the neighbouring kings, he may withdraw himself; or having installed the heir-apparent, he may set the army against the enemy; and when attacked by the enemy, he may take, as detailed elsewhere, such measures as can ward off dangers.