Lets act while we are thinking about where to act next. Start with KNOWN terrorist states, a little paving project or two... and then move towards what our investigation uncovers as it unfolds. This "think before acting" is predecessor to "lets not get hasty in our judgement" and then looking for a few suspects to try and then incarcerate for life. WE need to burn all who sympathize with this attack, or who harbor groups that do, to a crisp. Its time to take out the known garbage when the kitchen stinks... and not worry about finding the right trash can. Take em all out and the kitchen will start to smell better. After they are all gone, you can treat the whole room to disinfectant... and end the stench for good.
I hate pacifists. They are dangerous and the root of this terrorist problem around the world.