On Friday when reports starting coming in of the death of 'jihadi John' Mohammed Emwazi it felt that a symbolic blow had been made against Islamic State.
The events in Paris later that day suddenly made us all aware of just how difficult and bloody the fight against Islamic State with be for Western governments.
This attack feels more shocking because of the scale and the fact that Islamic State have taken the war to the heart of Western society in a major capital city like Paris.
The question of what we do next and how we can tackle and ultimately defeat Islamic State is so difficult to answer. I feel that we are at war with Islamic State but it's certainly not a conventional war that most people are familiar with.
My initial thoughts took me back to how I felt following the Charlie Hebdo attacks at the beginning of this year. Like then, Friday's attack wasn't just about killing innocent people enjoying an evening out; it's an attack against our very values and beliefs here in the West.
This is what I said in January:
"On an average day I rarely think about the ideals and values of the society that I live in. The attack on Charlie Hebdo has changed that. The week's act of terrorism is an attack on all of us."
I stand by this, and it's the reason why we should look to do everything we can in our powers to defeat Islamic State. I know that won't be easy, it needs to be done both militarily and diplomatically.
One of the problems I've always had with Islamic terrorism is that it's terrorism which appears to have no ultimate end game. When I say this I mean it's not conventional terrorism that we've previously been familiar with such as the IRA or ETA. With the IRA their aim was for a united Ireland, with ETA they wanted an independent Basque state. What does Islamic State ultimately want?
I do not see a resolution in which they would end their campaign against Western governments and even if we left them alone to consolidate their power in the Middle East would that really be something that would be beneficial for the region and the wider world?
Can we the West really co-exist with Islamic State? If they continue to engage in this war on our values our culture and innocent civilians we will have no choice but to take the fight to them.