It was 7:49 Friday night at Millie & Al's, a pub on 18th Street in the Adams Morgan district, and it looked like any other night. A hockey game flickered on the small television screen; elk antlers hung near the back wall next to a string of M&M Christmas lights; behind the bar, the light that signaled $1 jello shooters was not yet activated; working stiffs, tired from the week, unwound at the bar while friends laughed and chatted at tables. I had a bottle of Guinness in front of me and a pizza on the way, but I kept...