Cleon neglected to protect his artillery with an infantry screen.
Cleon insisted on assaulting enemy line formations in a column.
Cleon exposed his army to an enemy army without expecting battle.
Cleon had failed to make use of superior Athenian sea transport capabilities.
He took the wound while killing Cleon in a duel of the two commanders.
He took the wound while leading a surprise charge from the front.
He was struck in the eye by an arrow.
He took the wound in the ankle, where his mother had held him while dipping him in the waters of the Styx.
Several of the Spartan's allies, including the Boetians, would not accept the treaty.
The Spartan war party refused to accept the treaty.
The Athenian war party refused to accept the treaty.
Several of the Athenian allies, including the Corcyrans, would not accept the treaty.
Corcyra and Thebes.
Syracuse and Lesbos.
Megara and Heraclea
Corinth and Argos.
Athens's failures happened because they could not get a majority vote to approve them.
Sparta's failures were dependent upon the actions of unwilling third parties.
None, the two parties both abided fully with the terms of the peace treaty.
None, neither party ever had any intention of abiding by the terms of the peace treaty.
They did not realize that the Spartan ephors favored it.
They feared that doing so would provoke a new war with Athens.
They feared that doing so would provoke a war with Sparta.
They saw no advantage to themselves in concerning themselves with the matter.
Do what thou wilt shall be the whole of the law.
Athenian democracy was better than Spartan oligarchy.
The strong do what they can and the weak suffer what they must.
From each according to his abilities, to each according to his needs.
They did not trust the Melians because of their blood ties to Sparta.
They saw benefit in either crushing opposition or forcing surrender, but none in friendship.
They knew the Melians were simply hoping to buy time until Spartan reinforcements could come.
They were being encouraged to attack Melos by the Corcyrans.
The oligarchs were removed and democracy was established.
Trade between the two cities increased and Melos became wealthy.
The population was forcibly exiled to Sparta.
The men were killed, the women and children were enslaved.