Kautilya's Arthashastra 9.5.30

9.5.30

etāsāṃ catasṛṇām āpadām abhyantarām eva pūrvaṃ sādhayet //

Of these four kinds of danger, internal danger should first be got rid of; for it has been already stated that internal troubles like the fear from a lurking snake are more serious than external troubles.