What did they use in the Peloponnesian War?

Answer 1

The only thing that might have helped them be more cooperative was the impossible dream that they could forego their habitual way of settling their disputes without war. They went on fighting until Macedonia brought them to heel. This was only a temporary respite; they continued on fighting each other for centuries more.

Answer 2

Their natural disposition was fighting each other. The aim of the Persian Empire in trying to include peninsular Greece within its empire was to bring peace to the area, and stop these intercity fights spilling over into its empire. This 50-year attempt failed by 449 BCE when they gave up and undertook to leave the cities alone to their own devices. The Peloponnesian War ensued, and even after it ended, the continued fights between the cities went on. Had the Persians succeeded, they could have stopped the fighting.

Fifteen years after the Peloponnesian War ended but the fights continued on between varying adversaries, the King of Persia demanded a cessation and threatened to retaliate; this was known as the King's Peace. This had some effect, but the fighting went on until Macedonia imposed peace fifty years later.

Answer 3

A war does not need help.

Answer 4

Military and naval force and diplomacy.