Most people are busy surviving - in the USA and in other places as well. I am one of them, sitting in a relatively safe Europe that is not entirely overrun by nazis (just yet). 90 years ago it were my family members in Germany - while things gradually got worse for some citizens they still had to go to work, feed their kids, pay the rent. They were branded as nazis after they lost the war. Before the war they were just citizens of a country gradually sliding into authoritarianism, just like the USA is now.
When I read headlines about Israel and USA I feel some angry disbelief that this horror reaches me as a normal sounding news headline - like something I should just listen to and get vaguely annoyed about, not something that makes my heart feel rotten and my brain boil, not something that makes me want to take up arms and fight for what makes us humans instead of monsters. But then I have to think about rent and food again, and everybody around me does the same. So here we are - letting things happen because we are busy surviving, and because the media makes what's happening sound like just another headline.