Delta & WestJet Joint Venture Called Off: What Happened?

In late 2017, Delta and WestJet announced plans to form a joint venture for transborder flights. Well, almost three years later, the two airlines have withdrawn their application, just shortly after it was tentatively approved with some restrictions. What exactly happened?

Delta has long been focused on strategic equity investments and joint ventures. Historically Delta hasn’t been very strong in Canada, but that was supposed to change with this new WestJet joint venture.

With a joint venture, airlines can coordinate schedules and fares in eligible markets. The way I view joint ventures: