I was walking between two planes in the US, one coming from a foreign country and the other leaving for one, without leaving the building. The only way I could have let the banana loose to destroy New York would have been to run outside and huck it over a fence.
American airports generally don't have international-to-international airside transfers. In order to take the connecting flight, you must first pass though immigration and enter the US. You were planning to take the flight to Vancouver, but at that point, you could have chosen to visit the US instead.
There's really no way to do it. The basic issue is that the US has no outgoing immigration control. I have walked from an international departure gate to open air and encountered no obstacles of any kind in the process, although I did pass through a one-way spot. (And the reason for this was pretty trivial--major delay, I preferred the food options elsewhere in the airport.)
How do you have airside transfer when there are no barriers to leaving airside?
yes, I'm not sure the logistics but it's definitely done in other places.
Certainly in Australia if you are travelling international you go through outbound immigration control. I'm not sure what happens if you need to get out again for some reason after you "exit" the country. I assume you have to "re-enter" the country by circling through inbound immigration. Perhaps having no land borders makes outbound immigration control more reasonable.
It does seem like the cost of adding some secure departure lounges might be less than circling huge numbers of passengers through unnecessary immigration procedures, security lines, etc
I haven't spent too much time in New York, but I don't think there are a lot of commercial banana growing operations there that could be affected. The real reason is they can't be bothered to track who's going where, but what they can do is seize your stuff, so that's what they do.
