Casual
You are wrong. These are not arbitrary boundries. Something that most Europeans don't understand is that the states of the US are not sovereign countries, and have no rights to bargain or make treaties for themselves. Japan and Korea on the other hand can do this, as they are separate and sovereign countries. That is why 5th freedom is the proper term for a US airline flying between Seoul and Tokyo, but not the proper term for an non US airline to fly between Boston and Chicago.....this would be cabotage. Many foreign carriers bring their cargo into the US for further distribution. They are in and out of Chicago, Miami, JFK, and LAX all the time. The further distribution just happens by truck, not airplane.