Kautilya's Arthashastra 7.8.22

7.8.22

madhyamaś ced anugṛhīto viguṇaḥ syād amitro 'tisaṃdhatte //

Whoever of the two, the conqueror and his enemy, who may happen to have a friend in the same Madhyama king, helps a Madhyama king of true or truer friendship overreaches the other; for, by helping a true friend, he enriches himself, while the other incurs loss of men and money and the difficulties of sojourning abroad. When a Madhyama king thus helped is devoid of good qualities, then the enemy overreaches the conqueror: for, such a Madhyama king, spending his energies on useless undertakings and receiving help with no idea of returning it, withdraws himself away.