Extremists who train suicide bombers are rich and powerful people. It isn't possible to maintain an armed force the size of ISIS without large and continuous funding. They take the ignorant and foolish and make them feel important, they promise them paradise and persuade them that their 'martyrdom' is God's will. For ISIS the Islamic faith is a shield to excuse their evil acts, it is a distraction to direct the ignorant towards a misdirected violent ...response.
These controllers want the western, secular world to over react and do something equally extreme from frustration and anger. If we do respond in kind it will allow ISIS and their supporters to claim that the west is attacking all Muslims and draw frightened and vulnerable moderates towards them for protection. Such a scenario would create instability in every country that operates under a liberal democracy.
Now is time to be angry and a time to grieve but it is not time to attack ordinary people who have a different faith. If we frighten those among us who have a different faith then we fall into the ISIS trap.
Don't blame Muslims, Arabs, Pakistanis, Iranians or anyone else for the wickedness that has taken our people. Blame the bomber and blame those who fund them from somewhere far away. We must carry on living with freedom of speech and freedom of religion under the rule of law. Don't get drawn in by the hatemongers and don't lash out in anger. Hate the criminal and the crime not the religion and certainly not your neighbour