What's the Biggest Single Cause of Global Violence Today?

From What's the Biggest Single Cause of Global Violence Today?:

So Israel must be wiped off the face of the Earth. It's official policy according to the president of that well known democracy, Iran. It proves that whatever Israel does right is ultimately wrong. Pull out of Gaza, at astonishing personal cost to their own electorate, and somehow it works against them. They cannot protect themselves, surrounded as they are on all sides by warrior states, without being labeled the aggressors.

[Member of Parliament] Clare Short has decided to tell us that American support for Israel is the biggest single factor in global violence in the world today. Well, that clears up any worries we might have had about the causes of violence in Darfur in western Sudan, Zimbabwe, Burma, Chechnya, Rwanda, Northern Ireland...shall I go on? Is there a conspiracy theory to follow, Clare? The causes of global violence are global extremism, of any creed, in any guise.