I was thinking of opening a company in an underserved market where also neighbouring countries currently are not served very well. These countries are not member of any open market treaty.
Because of the border shape I was thinking of connecting two of the neighbour countries largest cities through the hub in my home country. I was now wondering if passengers were allowed to travel on this connection (via my hub) since it is technically a form cabotage. I know in real life there a often restrictions on this, for instance an airline from Korea may not sell a ticket with a routing from Los Angeles to Guam via Seoul since origin and final destination are both within the US.