The reality is that Britain needs a new hub airport. Paris has four runways, and so do Frankfurt and Madrid. Amsterdam has more, and American cities more still. Of course, sticking our heads in the sand won’t send us back to the stone age, but connections and prosperity go together.
But siting a four runway hub is not straightforward. Airports are noisy and countries have a choice. One option is to put an airport somewhere that works for passengers (La Guardia, Haneda, Dorval) and put up with the noise. The alternative is to put it further out (Newark, Narita, Mirabel) but then passengers do their best to avoid it because it takes longer to get to.
That is the way the current debate is framed. The proponents of a third runway at Heathrow have a point that people prefer to fly from Heathrow because it is the easiest airport to get to.