Clearly, the additional security measures put in place post-9/11 will act as a deterrent and thus increase safety. Clearly, the additional scrutiny of human beings, by human beings, will cause friction at times - as will arise in many other forms of human contact.

What is perhaps missing the point, when people complain about long lines and over-attentive security staff etc, is that the overall quality and effectiveness of security measures in the US is extremely good.

Many would be horrified to see some of the wayward and corrupt practises that go on in a significant number of international airports - airports with flights going to the US. What is in the bag that a corrupt airport security/Customs/baggage employee has put in the hold in Islamabad? Drugs, weapons, explosives? Take it from me, there are some incredibly shoddy practises out there and I would never presume to get complacent about the need to keep looking.