SPARTA stood as the dominant military power of the Greek world in 431 BC. Its supremacy was rooted in a formidable army. Athens, however, was rising with a powerful navy. “The growth of Athens and the fear it inspired in Sparta made war inevitable,” observed Thucydides, best known for his masterpiece History of the Peloponnesian War. Centuries later, Harvard scholar Graham Allison analysed 16 such conflicts since the 16th century and found that 12 ended in war. He termed this dynamic the Thucydidean Trap.