What does it mean to take responsibility for something? The Telegraph takes Blair to task for failing to take any reponsibility for the war in Iraq and all its consequences. His argument is that it is not he, or the British or the Iraqi public which are causing the violence but the extremists.
Yet if you deliberately bang your head against a wall, you are responsible for your injuries. It is entirely unconvincing to argue that it is not you, but the people who built the wall that are solely at fault.
In a complex situation, all parties will usually have some responsibility. And it is irresponsible to pretend that you have no choice but to carry on banging.