They have neither the resources, the support the terrain or the assets to wage a guerrilla war.
The best they can hope for is the odd riot and civil disturbance, but even that is not very likely.
In Britain there is a strong don't rock the boat attitude amongst many of the Muslim communities.
During the Cartoon frenzy, a number of young Muslims went to London with some placards with comments such as death to those who insult Islam, and remember 7/11 the London Bombing.
Within days they were disassociated by Islamic communities the men were arrested and charged , and were forced to apologies on Television .
While I am not discounting the Islamic threat, British intelligence and other assets are monitoring and dealing with them..
And remember we have over 50 years experience in these operations.
Experience gained fighting the IRA, INLA, UFF UVF and other terrorist groups, who were amongst the most professional and battle hardened to ever operate in the West.
In other words, "it could never happen here." I understand.