Thanks for the link. Also, I was just playing with routes, and it looks like a route (that I roughly constructed) under russia is still 100s of miles shorter than through Alaska (for the hypothetical CPH-HND route). I don't know if there are other issues with flying over any of those countries. And maybe with Alaska as a hub, it could end up being more efficient to fly there and then switch and onward to eastern Asia, although I thought that newer planes were favoring direct routes rather than huge planes between hubs, e.g. the A350 vs A380.

Not to mention, historically people who don't have to often avoid connecting in the US because I think there is / was an extra visa burden, even if it's just for transit. I think many people might avoid a route that makes them enter the US, though mayb things have changed and it's less of hassle.

http://www.gcmap.com/mapui?P=cph-ist-gyd-ala-pek-hnd;+cph-an...