The legend goes that big bad DL drew a line in the sand and ran them out. That's not exactly what happened. Both DL and AT absolutely dumped on them, but they were still willing to give it a go...right up until they were basically gifted an entire terminal in BOS. They were still very small then and growing as fast as they could they were still limited with what they could do. So they pulled the few planes they had in ATL and dumped everything they could into BOS. A blink of the eye later and they were the biggest airline in the history of BOS and absolutely dominate that market. It's their crown jewel and they feel they can reign unopposed there from now on.

And they'll still end up back in ATL.

That doesn't mean DL can't and won't fight back. I actually think we would. Ironically the perfect place to hit them hard in retaliation for nibbling at our toes in ATL would be to flex up BOS and dump on them there, while both DL and SW defended their turf in ATL quite handedly. Pry that jewel right out of the crown, or at least put some big cracks in it. DL could do that there while barely moving the profit needle across the larger network. The only way they could really fight back would be to self mutilate their yields in NYC, which they couldn't do for very long.

That could end up forcing another merger, but even that would benefit everyone. Fun times.