Sometimes in order to get people to act against an injustice, one needs to demonstrate how it affects them personally. I’m not talking about “what if something similar happened to you”, I’m talking about “you’ll really feel the effects of the war when petrol prices go up”.
It’s not usually something as trivial as petrol prices. You might have to say things like “the invasian of Iraq will fuel hatred and aggrevate would-be terrorists” indicating that it will ultimately make life less safe (rather than asserting that invading and occupying another country is simply wrong). Or maybe “intensive farming methods could result in contamination of our food supply” (rather than asserting that animals should not have to endure such appalling living conditions). It seems that we are more easily swayed by arguments that something is impractical or unwise, rather than simply unethical.
It’s selfish and prejudiced to make a moral decision based on how it affects you. You also shouldn’t assume an alterior motive when someone makes a moral argument (in order to deride the argument as self-serving). Arguments should be judged on their own merit, not by what someone wants to get out of it.
Are we really so immoral that injustice needs to have clear negative implications for us before we do anything about it?
On the other hand, is scare-mongering (rather than presenting an argument based on ethics) offensive to our potential for moral character?