Chanakya

The Arthashastra, traditionally credited to Chanakya (also called Kautilya), adviser to India's first Mauryan emperor, is a manual for running a state: taxation, spies, a professional bureaucracy and a "circle of states" in which your neighbour is your natural enemy and your neighbour's neighbour your friend. Scholars debate how much he wrote. Read the sections on foreign policy first; they show realist thinking two thousand years before it had a name.