I'm often impressed by the depth of the themes that Eiichiro Oda works into One Piece; whether he's touching on religion, arms proliferation, or systematic oppression. The latter seems to have emerged a major theme as our heroes have come into conflict with the powers that control their world, and I've been fascinated to see how Oda works it into his ongoing conflicts, examining how racism, segregation, and slavery can affect a people, and how much work it takes for them to emerge from generations of suffering. He had previously expressed the optimistic view that while those under oppression might not be able to let go of their hatred, they can pave the way for future generations to do so, but in volume 65, he gives us the flip side of that, demonstrating how decades (or centuries) of anger, even if it is justifiable, can institutionalize a vengeful spirit in people, leading eventually to pure nihilism. We see this most clearly in the main villain of the arc, Hody Jones, the leader of the New Fish-Man Pirates, who has gone beyond vengeance against the humans that have oppressed his people and begun also attacking any fish-men who befriend, help, or collaborate with them. After launching a scheme to take over Fish-Man Island (fueled by steroidal drugs that have begun to drive him mad), he ends up deciding to wipe the island and its inhabitants out entirely, no longer caring who is the victim of his destruction. When questioned what happened that made him so hateful, his answer is chilling:
The closest real-world analogue I can think of for this is terrorism, people who might feel they have a righteous cause, but have become so perverted and distorted through anger, hatred, and religious brainwashing that they have no sense of what is just or right and are willing to destroy anything or anyone in the name of their cause, which has become meaningless. Oda confirms this link by invoking the term "holy war", and even drawing some parallels to real-world terrorism:
Even though this is all background for a big battle, it's a fascinatingly deep examination of the cultural forces that can drive people to do horrible things. I'm regularly blown away by the ideas that Oda builds his stories on; he could just be throwing goofy characters and awesome action onto the page, but instead, he's building a complex foundation to everything, and delivering a message to his readers about the way the world works and how it can be changed for the better. This guy is pretty amazing.