Monarch Man - you raise some very interesting points that I've obviously overlooked in the heat of the moment. In my day you didn't have to worry about security and there was virtually 'open access' to the flight deck with kids and families visiting, pax sitting in the flight deck for landing and take off etc. In fact the Middle East and Pakistan were great places to visit. Since 9/11 that has all gone and that part of the world is now is more dangerous than ever.
You raise the point of 'sleepers' which in my view is critical to aviation as so many seem to be radicalised towards fundamental groups. There could be someone that could slip through the net and cause utter devastation. What is the answer? A difficult one. Even with security checks to get access to air side does not guarantee 100% safety. Perhaps carriers need to go down the EL-Al route and carry onboard sky marshals maybe one answer.