On Monday morning I visited Leicester Central Mosque, where I met with senior local officers from Leicestershire Constabulary and leaders of the local Muslim community.
In October last year, the Home Secretary banned a planned march by the far-right pressure group the English Defence League (EDL) through the city.
I heard how police officers and the local Muslim elders worked together to calm the situation, preventing young Muslim men from going onto the streets and confronting members of the EDL.
As I said in an interview on BBC Radio 5 Live recently, violence and intimidation are totally unacceptable in any form. You can't tackle extremism by being extremist yourself. You don't prevent hatred by being hateful yourself.
The visit was also a powerful reminder of the need to draw a clear distinction between Islam - a peaceful religion practiced by over a billion people - and Islamist extremism, a political ideology that perverts the teachings of the Koran.
Put simply, the ideology of extremism is the problem; Islam emphatically is not.
This was the point that David Cameron highlighted in his speech on the failure of multiculturalism last weekend.
As the Prime Minister said: "under the doctrine of state multiculturalism, we have encouraged different cultures to live separate lives, apart from each other and apart from the mainstream."
We must do more to build a stronger sense of shared national identity and be tougher about confronting groups that promote extreme values.
So the Government will not engage with organisations that do not believe in freedom of speech, freedom of worship, democracy, or equal rights.
Such groups should not receive any public money or share platforms with ministers. And they must be barred from spreading their message in publicly-funded institutions like universities and prisons.
As the Prime Minister suggested, we must end the practice of "hands-off tolerance" and actively promote our national values.