The recent killing of Americans in Libya by a mob of protestors who were responding to an intentionally offensive youtube video, created by Sam Bacile and friends, illustrates a fundamental truth.  Extremism begets extremism.  Killing begets killing. Violence begets violence.

It is a truth that directly relates to the cycles of incivility that we see in American politics and a truth that social psychologists often study, because group level reactions to conflict, extremism, violence, and incivility/demonization are fairly predictable; they incite more of the same.  Indeed, there is clear evidence that Sam Bacile, Terry Jones, Osama Bin Laden, Charles Manson, and other extremists understand this implicitly and commit their extremist acts with the idea of inciting a wider war.  In this case, a desire for a wider conflict is what the Libyan Mob and Sam Bacile have in common.  Psychology research backs their methods.

• Interviews in Rwanda illustrate how the humiliation of some led to a desire to counterhumiliate others and ultimately to genocide. (Full article here)
• A large body of research shows that being threatened by reminders of one's mortality leads one to want to punish and derogate those who have a different worldview.
• Threat and mortality salience also increases the tendency to stereotype outgroups.
• When violence occurs between groups, members of a harmed group can be motivated to retaliate against innocent members of the perpetrator's group, leading to cycles of violence and vicarious retribution. (also see here)

Given the reliability with which extremists can create cycles of violence, it remains imperative that those of us who want reduced extremism, incivility, and violence realize the situational causes and consider how to frame things as a cooperative goal of moderates vs. extremists, instead of a Muslims vs. the West frame that extremists on both sides would prefer.  It's an imperative that Martin Luther King put as follows:

Hate begets hate; violence begets violence; toughness begets a greater toughness. We must meet the forces of hate with the power of love… Our aim must never be to defeat or humiliate the white man, but to win his friendship and understanding.

The ultimate weakness of violence is that it is a descending spiral, begetting the very thing it seeks to destroy. Instead of diminishing evil, it multiplies it. Through violence you murder the hater, but you do not murder hate. … Returning violence for violence multiplies violence, adding deeper darkness to a night already devoid of stars. Darkness cannot drive out darkness; only light can do that. Hate cannot drive out hate; only love can do that.

– Ravi Iyer