The terrorist playbook has no country, the most rudimentary methods with the element of surprise and the willingness to die. --Like in, Nice France, London, and now New York, these tragedies are like mini versions of flying a plane.
It can happen anywhere, anytime. A lot of progress has been made, the number of thwarted terrorist attempts far exceeds the tragedies, and some luck, too, like the bomb that went off in The Chelsea neighborhood a couple of years ago did not kill anyone but did injure 30.
In thinking about the recent methods of plowing through crowds at high speeds there are very vulnerable places like the west side highway bike and pedestrian lane. Maybe the engineers could look at solutions? Block car entrances with a gate only to be opened by LE, Fire & rescue? Alarm it? When a vehicle enters pedestrians will know it through the sound of alarms? Where are our most vulnerable places?
Everything goes hand in glove--immigration, targeting radicalization, urban solutions, and government funds to keep our anti-terrorism programs working with LE strong.