Yesterday was as picture-perfect a day as that September 11th, but 23 years later, nearly a generation ago. As it happens, I spent part of it on class readings about 9/11 and the politics of fear. 

One of the points I took home from these articles was terrorism’s legacy of anxiety and containment, of divisiveness — there are those who are terrorists (or look like them) and those who are not. 

In class last night, a colleague mentioned something I hadn’t thought of in a long time: threat levels. Remember those colors — red, orange, yellow? They were part of the Homeland Security Advisory System, I learned from Wikipedia today. In place from 2002 till 2011, they affected the level of security at airports and public buildings. 

Some class members were babies then; they had no memory of those. The threat index they’re most familiar with are air-quality levels.