Most of us will have been shocked to see the graphic pictures and hear the harrowing accounts from Woolwich. As the founder of a charity that exists to bring communities together, I woke up this morning with feelings I had not experienced since the riots. I felt again that numbing sense of disbelief, that mourning and sadness at accepting the reality followed by that overwhelming desire to find a way to mend what feels broken.
Over the coming days, the country will go through much soul-searching. Why did this happen? How did it happen? Who is to blame?
There will be many who look for someone to blame. A scapegoat will be sought to reassure us that someone is at fault. In this search for a scapegoat, people will turn to the unfamiliar; to that which they do not understand. Some on the far right will do this deliberately - seeking to breed division and hatred. But most will not. Instead, lost, confused and fearful, they will simply follow - placing the blame on a community they do not know or understand.
This search for blame is the very thing we should fear the most. The lack of understanding, the distance and disconnection between our communities is the very thing that should worry us. Far too few British non-Muslims have British Muslim friends to discuss last night's events with. This gap in our friendships, this hole in our relationships is the division that the terrorists want to exploit. It is this gap, this disconnection that makes our country weak.
This should be our call to action. For without action the gaps will become greater - especially as we become more diverse.
And we will become much, much more diverse. By 2030, a third of all citizens in the UK will be non-white; 20 years later, we will be the most ethnically diverse country in the rich world. This is a change for which we are largely unprepared. Our education system illustrates the problem. We retain one of the most ethnically segregated set of schools anywhere in the world - only three rich countries have a more segregated system. A school system where mixed communities separate at the school gate, where predominantly Muslim and predominantly Christian schools are allowed to sit side by side, where young people fail to gain the very network of diverse friendships that they will need to navigate the future.
At a time when we need to be sowing the seeds of understanding between communities, we have a school system that sharpens our divisions. And this is just one part of our problem. For too many of us our friendships are equally non-diverse. We lack easy opportunities to meet and befriend those from different backgrounds and walks of life.
It is not good enough to do nothing about this. Too many times I have heard politicians and commentators lament that you cannot force people to mix and therefore we must do nothing. This is madness. You cannot force people to stop smoking, but you can decide whether to let them know that it causes cancer. You cannot force people to take exercise, but you can decide whether to offer PE in schools. You cannot force people to read to their children, but you can give them free books when their children are born. We do all of these things - and yet on the pressing issue of building connections - we do almost nothing.
Yes you cannot force people to mix, but you can invest in programmes that make it attractive to do so. Programmes like National Citizen Service bring together thousands of young people from all backgrounds together each year. We must redouble and expand this work. You cannot force people to mix, but you can reward schools that market themselves to all sections of the communities they serve. The pupil premium is in place - what price a diversity premium - extra funding for schools that represent their community? All of this terrain is complex and sensitive, but if Woolwich - and the response to Woolwich - teaches us anything it is that we cannot just do nothing.