Without trusting one's foe in reality, one should treat him in such a way as if he trusted him completely. One should always speak sweet words to one's enemies and never do anything that is disagreeable.
अमित्रमुपसेवेत विश्वस्तवदविश्वसन्। प्रियमेव वदेन्नित्यं नाप्रियं किंचिदाचरेत्॥