We wouldn't need to tell them, they know. The radical elements in Iraq who actually perpetrated the violence in pursuit of extremism are responsible for the violence.
There is a reason why Kurdistan is one of the most peaceful and developed regions in the Middle East: they act the way you must act to be a prosperous modern people. The violent radicals who squandered the post-Saddam opportunity to build a modern Iraq are to blame for the killing and the chaos.