When a teenager - and I know this is going to surprise you - I was an aircraft spotter, military division. There were four of us, and at half term we would set out in a battered Ford Prefect on long, looping one-day expeditions from our South London fastness: meticulously planned, OS maps all the way, to take in as many military airfields as could be reached in one day, timed so that sun-up found us and our telescopes at the first stop, and sundown at the last. (Our record was 12. Our extremities were Kemble in the West, Upper Heyford to the North, and Honington to the East. In between stops we would recite from memory whole Monty Python sketches and ISIRTA skits ... party on!)
Anyhow: the IRA campaign of the '70s was in full swing, but security at these places was typically laughable. It was by no means unusual to be able to wade unchallenged through a hedge and approach fully operational military aircraft across the grass (I have the photos ...). But we and our confreres were the only ones that did. It occurred to us that the IRA must either be stupid, not really trying, or in some strange way strategically averse to causing millions of pounds worth of damage and tying up thousands of British military personnel at minimal risk to themselves ...
Back in 2016, I have been travelling a bit recently and had cause to rehearse the same observation, this time in respect of civilian transportation systems. It would be crass to give details, but I couldn't help noticing (as I am sure we all have) that security is *less than ideal* in a great many awkward places.
We could go through the same conjectures again; and I am led to the conclusion that we may be on a knife-edge as regards easygoing, easyjetting international transport for everyday purposes. Of course everyone will keep dancing until the music abruptly stops. There was a dip in air travel after 9/11 but since then air passenger miles have
doubled (sic), thanks to better aircraft, more competition, more demand at low prices, more movements of people from developing countries, and
Not Very Much Trouble. I suggest that it stands to get a whole lot more difficult, time-consuming - and of course expensive. Schengen or no Schengen.
Hope I'm wrong.