If we distrust everyone with a certain accent, we will spend all our energy and time investigating the wrong people. It would be much more productive to trust each other. Then those that are not deserving of our trust will quickly stand out and be easier to locate, investigate and deal with proactively. Meanwhile, we will be healthier and happier ourselves. This is a battle between the ideals of a religious Theocracy and the institutions of Democracy - two systems of thought that cannot coexist.
Theocracies have no concept of personal liberty and despise the concept of freedom.
Merely having free neighbors is a threat to them, an insult to what they believe, and perhaps even an intolerable temptation for which they feel an overwhelming guilt. So freedom itself is the enemy. They want to kill freedom itself. In this battle between Freedom and terrorism, the terrorists are already winning. Antiterrorist legislation destroys many of our Constitutional rights with little effect on the terrorists.