Kautilya's Arthashastra 7.5.17

7.5.17

balavantam anyāyavṛttim abhiyuktaṃ prakṛtayo nānugṛhṇanti, niṣpātayanti, amitraṃ vāsya bhajante //

The strong enemy of wicked character should be marched against, for when he is attacked, his subjects will not help him, but rather put him down or go to the side of the conqueror. But when the enemy of virtuous character is attacked, his subjects will help him or die with him.