The really hard thing is to act moral when we are afraid. It's easy to say how moral and righteous we are in times of peace, but when stuff goes wrong then a lot of people will give up freedom for a sense of security (you may have heard a really famous quote about this). With Japan I think everyone admits it wasn't the moral thing to do, but many argue that it was a necessary evil. And you should be wary when you hear those arguments, so we don't repeat history.