Look... Islam, as a theology, isn't the problem. There is pretty much no "belief set" that inherently causes mass murder by itself. It's all about circumstance and application.
The way Islam is used as a method of control/power/oppression in certain regions leads to a percentage of the population being radicalized. Furthermore, when you have religious leaders -- like the Ayatollah in Iran -- preaching death to Israel and the West... how do you not expect some people to take it to heart? When more minor leaders preach to their followers that slavery is OK, that non-Muslims are sub-human, etc... how do we not expect some people to take that to heart?
Even some countries like Saudi Arabia that are ostensibly "allies" have religious and political leaders that preach "death to America" and fund terrorism.
So it's not about Islam, per se, it's about how these people in positions of power are using Islam. These attacks are never going to stop until these people are eliminated... whether that's over time through education or through military action, the only way this stops is if those leaders don't exist and can't drive people to this kind of action.