How crucial is O’Hare International Airport to the future of Chicago? The city would be marooned in the global economy without it. If O’Hare ever loses its position as a top-tier hub, Chicago becomes a bigger Milwaukee — a nice enough place to do business but not competitive with Atlanta, Los Angeles and Dallas for large-scale employers.

That is why the $8.5 billion megadeal Mayor Rahm Emanuel is negotiating with United and American and other airlines to overhaul and expand O’Hare is crucial. O’Hare will either drive jobs to Chicago or drive them away. There’s a reason Amazon says a top criterion for the site of its second headquarters is a city with an international airport: because that’s how business is done, by executives hopping flights to Paris, Beijing or Sao Paulo, as well as to New York or Seattle. We bet Emanuel couldn’t wait to tell Amazon CEO Jeff Bezos of his plans.