Originally Posted by moondog

NRT worked as a hub because it was also the closest international airport to the largest city in Japan. Since this is no longer the case, demand for O&D traffic is a fraction of what it used to be. United solved this problem by launching direct flights from SFO, ORD, and EWR to destinations previously served via NRT; it's been a 20+ year buildup. American and Delta, by contrast, don't really have viable West Coast hubs; like UA, they sort of dabble in LAX, but that's blood bath competition wise. SEA, in spite of its geographical advantage (closest US market to Asia) pales in comparison to SF and LA. Furthermore, UA's domestic feed into SFO is far stronger than DL's into SEA. As much as I dislike flying transcons to SFO (where upgrade space is often a pipe dream) followed by transpacs, at least I usually don't need to double connect.