Originally Posted by
moondog
Hg
They could easily run boats as far away as Thailand to/from skypier. If they did, nobody would claim that hkia is part of Thailand. The same logic holds for various points in the PRD, but all of which are in the same country.
Given the original example given was Basel, in France, with a customs road to Switzerland, and put under the heading of airports that serve two countries, it seems HKIA is very much responsive - you can land in HKG and emigrate either to Hong Kong or, via a ferry, China or Macau. (although, arguable with Hong Kong SAR - One country, two systems).
I don't think anyone has identified airports that are a closer example to what's originally posited, other than Tijuana. Having an airport that serves two states doesn't quite get it.