What 411A fails to realise is that the USA went overboard after 9/11. Before then, the rest of the world had been experiencing terrorism (some funded by USA citizens by the collections in "Irish" pubs) and had got used to security checks.
No, the USA in typical arrogant fashion carried on with no airport security (your friends could accompany you, unchecked, to the departure gate).
After 9/11 they panicked, created the monstrosity called the TSA (initially the most amateur, over-powered agency it was possible to imagine), and proceeded to lecture the rest of the world on security procedures. These procedures, as the Chairman of BA has commented, are often not carried out on US domestic flights. And what were the 9/11 fllights - domestic flights?
Septics - don't you love 'em.
Fred