Quick questions on Pericles' foreign policy and the outbreak of the Peloponnesian War: HSC Ancient History

When Sparta's final embassy reduced its terms to a single condition, repeal the Megarian Decree and there need be no war, Pericles rose in the assembly and argued against any concession. Thucydides reports the speech at 1.140 to 144, and it is the central source for Pericles' foreign policy. Three strands run through it. First, the legal case: the Thirty Years' Peace provided for arbitration, and Sparta was refusing it, so Sparta was the one breaking the treaty.

Pericles matched his diplomatic firmness with a clear-eyed military plan that flowed from one hard fact: the two powers were strong in different elements. Sparta led the finest hoplite army in Greece and could not be beaten in a pitched land battle; Athens commanded the sea and could not be beaten there. Pericles' strategy was to refuse to fight on Sparta's terms and to make Athens fight only on its own.

A quarrel between Corinth and its colony Corcyra over the city of Epidamnus escalated into a naval war. Corcyra, which had one of the largest fleets in Greece, sought an alliance with Athens. In 433 BC Athens agreed to a defensive alliance and sent ships, which fought at the Battle of Sybota.

Potidaea was an awkward hybrid: a colony of Corinth that was also a tribute-paying member of the Athenian empire in the Chalcidice. Fearing revolt, Athens ordered Potidaea to pull down part of its walls and expel its Corinthian magistrates. Potidaea revolted instead, with Corinthian and wider encouragement, and Athens laid siege to it.

The sharpest and most contested grievance was Pericles' own initiative. The Megarian Decree excluded Megara, a small state on Athens' border and a Spartan ally, from every harbour of the Athenian empire and from the Athenian agora. It was an economic weapon rather than a military one, but for a small trading state it was strangling, and Megara's allies treated it as an act of aggression.

"Assess whether Pericles caused the war" needs an explicit verdict; "evaluate the strategy" needs a judgement on both its logic and its outcome.