Am I weirdo for thinking it's actually easier to work sort of backward in something like this order. (If you're trying to convince "typical uneducated, indoctrinated American" that America and its allies have done horrific things, specifically in the last ~80 years, that have caused all of the current strife)

Start with the Iraq/Afghanistan wars. Everyone (should, rightly) hate W and Cheney, et al. It shouldn't take much to convince them that these wars were not a response to 9/11. Not really. They were wars of opportunity and used 9/11 as a false reasoning. (Saudi Arabia would've been the target if vengeance was actually the goal- specifically unseating the Saud family and bin Laden family from power)

Then go into 9/11 history. Show them that Osama actually had reasons which he listed. Hey, Palestine was on that list... You don't (and probably shouldn't... ) need to "defend" Osama. Just point out that he had reasons and many of them were valid. His religious fundamentalism was a direct result of US and Israeli aggression in his home region.

If you successfully get someone on board that Osama was a person with thoughts and feelings and reasons for actions. And also that America did horrible mass murder (genocides, many would argue) in Iraq/Afghanistan not as revenge or to fight terror but to enrich PMC owners, oil corporations, etc. and with hopes of outright just selling off rights to minerals and oil to American corporations. Same reason for all imperialist wars. Then you can wrap back around and be like "just like Osama had his reasons, so did/do Hamas. You don't need to agree with their reasons or methods, but understand that they do have reasons and those reasons are not because of some dumbass made up grudge between religions, it's because settlers came in the early 1900s up until 1948 when Israel was formally established and did mass murders, land theft, rape, everything bad one can imagine. And it only got worse from there with mass ethnic cleansing for decades all the way up until today."

I guess I'm saying it's probably effective to first delegitimization the US state. Bush makes that easy. Then show the legitimacy of some of the claims of Osama. Thus humanizing Arabs and making them not mindless animals as the media portrays them. And finally hope that they can see how moronic they were being and actually listen to the oppressed and ignore the oppressors. The hardest part is probably getting over stigma because of the holocaust. The fact that Israel weaponizing the fucking Holocaust in such a way is beyond description insane and disgusting. But, they do it constantly, and people fall into the trap (I did for a long time. Probably many people here as well). It's probably best to just stick to "Even if all this murder is "justified" due to the Holocaust 80+ years ago, the Palestinians had absolutely nothing to do with that. Especially the ones alive today." And then just stick to what Israel is doing now, ignoring all appeals to "but! Holocaust?"

Btw, for many people, the sticking point is "Osama had a lot of true points." The important ones about US imperialism, people won't accept. They literally do not have a framework in their brains to place the US being an evil empire and Israel being basically a vassal state or whatever. So if you can get them over that hurdle, that the US does evil stuff on purpose for the purposes of being evil (to steal and murder), that's basically the entire thing there... but good luck... seriously, people's brains are mush on this stuff. By design of course. Can't have citizens of the empire becoming suddenly aware that they are the baddies...