in the wake of the Brussels Attack, the Fear Level must be waaa-ay higher than the DHS "Threat Level".
The mundane setting of the bombing (air port subway) imprint themselves on the average news consumer almost all of whom must utilize such mundane settings in their daily life and thus can easily project themselves into notional carnage.
Fear is an emotion....and emotions have to be ruled, but they must be ruled from a place of understanding or else panic and or craziness ensues.
As liberals we tend to over rationalize (that Utilitarian Mantra "The Greatest Good for the Greatest Number" undercuts us in situations like this) attributing the fear to demagoguery at home and religious frenzy abroad.
It bears repeating that high body count or low, the fear comes from a real place and we are gonna have to abide in that real place understanding the "emotional content" even directing our response to that content while staying rational.
And that is the hardest mission at a time like this....and I write that as someone who has to take a poorly run indifferently secured subway every day.