'Muslim' is not a political party. 'Muslim' is not a single culture. Muslims go to war with each other. There are more Muslims in India, Russia and China than in most Muslim-majority nations. 'Muslim' is not a homogenous entity.
Not all Muslims wish to express themselves in public through a communal religious identity. Identities are multiple, and some may wish to speak instead just as citizens in their professional capacity, through their political party, or their neighborhood body.
The only way we can challenge Islamism is to engage with one another. We need to make it as abhorrent as racism has become today. Only then will we stem the tide of angry young Muslims who turn to hate.
Increased sympathy for an Islamist cause, lack of integration, and the absence of acceptance of Muslims into British society makes it harder for Muslims to challenge Islamism and tough for non-Muslims to understand it.
I can say with a level of confidence that Islam is not a religion of war, only because the majority of Muslims don't subscribe to that perspective, not because there's something inherent in the text that tells me it's a religion of peace.