The very definition of the word "terrorism". Terrorists want to spread fear of terrorists and make us change our lives, abandon our freedoms.
And when I look at the "security" which has creeped into all our lives... mass surveillance, the TSA, anti-"money laundering" laws, free-range racists running up and down through our countries spreading anti-Muslim hate... we are tearing down our foundations of society because we are afraid of... what exactly?
Most of the legitimate concern over terrorism is fear of WMD use. If you estimate the odds of such an event are low by looking at the frequency of terrorist deaths in the past, you're doing it wrong.
Terrorism is a propaganda word used by the bigger powers precisely because it has misleading connotations.
Problem is: the fucking ISIS men on the ground believe that they are doing good for Allah. They don't listen to reason.
In reality they were enforcing a colonial order https://www.youtube.com/watch?v=CvZRsdHgxgA and the locals are fighting back in an attempt to secure power locally, not give it away to foreign masters and watch them grow more powerful as a result.
We in the West must ultimately favor our own victory in such matters. The main reason ISIS must listen to is the West can't tolerate their insubordination, culturally and economically. It upsets the capitalist global order. We won't have enough trade with territories that chose not to develop economically in order to preserve old customs or prioritize local economies above ours.