Well aware that Mexico is North America, but so are Costa Rica and Panama if you want to get into tectonics as opposed to geopolitics; both countries sit on the Caribbean plate, even though they're further south than CCS... Re: SYD... Aside from the emotional rush some people and employees get from seeing the route map with far flung lines, AA decided long ago they don't need to be on every continent with their own metal. In the South Pacific, the QF partnership continues to deliver results (and it has for over 20 years), so why break what isn't broken? DL's situation with VA is different... they're 78% owned by other airlines: ~21% stake with Etihad, ~24.5% with ANZ, and ~22% by SQ. That poses considerable risk to DL, so they have to maintain a presence. UA's situation is more similar to DL's than it is to AA -- they have a more established partnership with ANZ to flow traffic from Oz via AKL, but balance out some of the risk of that going away by maintaining their own nonstops from MEL and SYD.