Why was Thucydides’s History of the Peloponnesian War an important contribution of ancient Greece?

It describes the Acropolis’s role in the war as providing a place of defense and shelter.
This work records the war between Greece and Persia in an attempt to explain the conflict.
Thucydides recorded both the Greek and Spartan sides of the war to ensure that the history was correct.
It was the first time that the Greeks had recorded a history of a war, even though other groups had recorded history.