A lot of people struggle with the idea that they can perceive themselves as good people, and still realize they are doing bad things. "If I'm doing something it can't be bad, because I'm a good person."

Or on the other side of the coin, *any* action against a group of people that doesn't fit some arbitrarily decided standard of moral purity is justified i.e. conflating thinking that what is happening to the Palestinians is moral with agreeing with Hamas.