There was nothing inherently accusatory or upsetting in the Government’s letter to Muslim leaders all across Britain, other than the fact that it was sent to Muslims alone. At the moment it is true that religious extremism is focussed on Islam, but this has not always been the case. We know from the violence in Northern Ireland that Christians too can terrorise to achieve a goal. The Jewish Stern Gang killed large numbers in Palestine in the period immediately following WWII.
A letter was in order but it should have been sent to all religious leaders in the UK. They all have a responsibility to the rest of us and to each other. In particular they share a huge responsibility towards the rising generation. If there was a message to convey which in the present context may apply to some more than others, it is wiser to avoid singling anyone out. The fact that it was sent in the form that it was and only to Muslims tells us more about the senders than the recipients.