Wet pavements cause rain

The NYTimes has a piece drawing a parallel between the UK's unfortunately named "ring of steel" and a walled fortress. The "ring of steel" is a network of barriers, checkpoints, and most importantly, video cameras, that track movement within central London

FOR more than a century now, winged dragons flanking a shield have guarded each entrance to the City of London. In recent decades, this coat of arms has been reinforced with an elaborate anti-terrorism apparatus known as the "ring of steel," consisting of concrete barriers, checkpoints and thousands of video cameras. City planners call the system, set up to defend against bombings by the Irish Republican Army, "fortress urbanism."

Perhaps no city in the Western world is better equipped to deter terrorist bombings. Yet the two waves of attacks this month have demonstrated that in London, "fortress urbanism" is far from impregnable.

Like the simple wooden ladder that was used to circumvent a castle's stone walls and moat, determined terrorists can still find tools to strike almost at will, even if their plans do not always succeed, as apparently happened last week in London.

This seems to be the exact opposite description of reality. As I wrote recently in "moats vs policemen" the only alternative to raising barriers and becoming a fortress is to let everyone in, but then carefully watch them to find wrongdoers. Instead of classifying surveillance cameras as part of a "fortress" strategy, the NYTimes should instead characterize them as what they are -- the only credible alternative to a true "fortress". (A surveillance based approach is also, IMHO, more likely to be successful).