Yeah I know. But I don't like to recommend just random topics, because when I do, I've noticed that people just go "oh wasn't interested in that" so I'd rather ask a bit about what topics and time periods people might be interested in, before recommending.

And to be clear, I don't really have a specific book or books in mind that radicalized me. It happened by reading tens, or a hundred, books in the period of 10-15 years. So in that I can't give a recommendation, other than, just start reading about stuff. Start with something you wanted to know, wanted to know more about or were interested in, then during reading that thing, note down anything else that comes to mind that might interest you. Either something the book mentioned or something that popped in your mind randomly. Then get a book about that thing. Repeat.

That's how I got sunk into this hole of reading about history. I just go "huh, what's that about?!" and proceed to find out. /r/askhistorians subreddit has a excellent reading list in their wiki, its sorted into periods and topics, easy to search. That's a good place to start.

You want something strictly relevant to all the messes we're in today?

The Hundred Years' War on Palestine and The Ethnic Cleansing of Palestine are must reads. Round them off with Beyond Chutzpah: On the Misuse of Anti-Semitism and the Abuse of History

Then read Inventing Reality: The Politics of News Media and Manufacturing Consent (obligatory fuck pedo-associated and possibly pedo Chompsky).

Take a break from reality and read a quick fiction: The Trial.

If you're not radicalized by anger at this point, you're one of the baddies.