Athens voted to sail for Sicily after the man who warned against it named the price

In 415 BCE the Athenian assembly debated sending a fleet to Sicily. Alcibiades urged conquest; the cautious general Nicias argued against it, warning that Sicily was too populous and too distant to rule. His warnings were heard — and overruled.

Nicias then tried a second move: he named the price he believed would make the assembly refuse. Telling them the force would need overwhelming numbers of heavy infantry, cavalry and transport, and 'as much money as possible' from home, he expected the sheer scale to end the debate. Instead the assembly 'became more eager for it than ever' and 'all alike fell in love with the enterprise.'

The assembly gave him the very force he had described: 134 triremes, 5,100 heavy infantry, and the most expensive single-city armament Greece had seen. Nicias, Lamachus and Alcibiades were appointed to command it — the dissenter was sent to lead the thing he had argued against.

Two years later the expedition was annihilated. Trapped in Syracuse's harbour, the fleet was destroyed or burned; the retreating army was cut down near the Assinarus river. Both Nicias and the reinforcement commander Demosthenes were captured and executed. Thucydides treats the dissenter-made-commander as the heart of the disaster.