Saffy-
Having dealt with bullies and abusers my whole life, I can honestly say that the only thing that works for me is to stay home and only "socialize" with the three other people who live under my roof, and the very few people we allow through the front door. This way, I CAN control my environment.
Maybe this isn't healthy by societal standards, but the family under my roof and the people I allow under that roof are enough for me. Disturbed doesn't even begin to cover how I feel about the things I read in the news every day. Mind numbing gossip. Increasing violence. Shallow materialism. Disgusting levels of greed. Parents murdering their children. Nope, I might not be able to control the outside environment, but I can disengage from it until people get a clue.
As for bullies, assertiveness only goes so far. In order to deal effectively with bullies, they need to be on the receiving end of a verbal can of whoop ass by EVERYONE who is exposed to it whether they are the victim or witness to it. If EVERYONE, whether it is family, workplace or school stood up to the bully and let them know in no uncertain terms that bullying would NOT BE TOLERATED, it might just make a difference. Otherwise, why should the bully change? Their bad behavior has always gotten them what they crave...power, attention, material goods, an outlet for repressed rage, whatever. It's like any addiction. Why should a bully change when others just keep making excuses for him/her? The bully won't change, the bully just goes and finds a new target. Intervention by EVERYONE involved is key. IMHO, witnesses to bullying who do nothing are just as bad as the bully. They condone the abuse of others.