LONDON -- I recently traveled to Paris from London. It takes two and a half hours by train. We are neighbors, our histories and populations intertwined. My 10-year-old granddaughter will go there this week with her parents as a birthday treat. She loves everything she has learned about Paris. So, like other Londoners, and citizens of free societies everywhere, she was horrified by the recent atrocities there. I suppose, she said, it could have happened here.