Two major analyses stand out among innumerable others. First there is the author's motivation: what did Thucydides intend by writing this down? Then, there is the question of today: what does a modern person learn by reading about wars that happened thousands of years ago? By understanding these two questions in tandem, the reader can begin to see this History as a commentary not of one singular event, but of human nature and their propensity to be at war.
Thucydides explains why he believes the war began. He feels that Athens was growing at a rate that threatened Sparta's sense of power. He reports that Sparta is a powerful nation because of their use of military prowess. He explains their brutality and strategy, their commitment to absolute victory, and the importance of fear and power in their social order. Of course, with a government like Sparta's, Athens political and economic rise to power poses a threat.
What this could mean to a modern person might be that change is always going to upset those in power, especially when the power is built on force. The dynamic of power is both economic and political, while also being tactical and military. For instance, if Sparta can defeat Athens, then the growth of Athens will be markedly reduced, especially if the whole world is watching (which they were). So, Athens must be able to execute a military dominion to protect their growing economic power.
