Gate 42 at LAX. A Southwest 737 pulls in from Denver, bags still spinning on the belt. Two hundred feet away, an ANA 787 is boarding for Tokyo Haneda. The question isn't whether those two flights can connect. It's whether the airline sitting between them was ever built to make that happen.
Southwest was not. Its entire network runs point-to-point — city to city, no funnel, no fortress hub. That's the efficiency engine behind its low-cost model. But it also means Southwest has no natural architecture for feeding long-haul widebodies. When Delta hands passengers to ANA at LAX, it does so through a coordinated hub with aligned schedules, codeshare ticketing, and through-checked bags. Southwest has none of that machinery.
The new interline agreement with ANA is the workaround. And it matters that ANA is now Southwest's fourth Asian airline partner — this isn't accidental. Southwest is deliberately building Pacific-facing connectivity without operating a single transpacific route itself. All connecting itineraries terminate at US gateways where ANA already flies: LAX, SFO, ORD, IAD, JFK, HNL.
But the mechanics are messier than a codeshare. Interline without codeshare means separate ticket issuance — two bookings, two check-ins, no guaranteed through-baggage. If the Southwest leg runs late, ANA has no obligation to hold. The booking funnel is fragmented, which suppresses conversion. Southwest's historical absence from GDS systems compounded this for years, and while that's improved, the friction points remain real.
What Southwest is actually purchasing here isn't revenue from connecting passengers. It's relevance. Roughly 15% of US domestic travelers are ultimately heading somewhere international. For a carrier that built its identity entirely around domestic simplicity, that's a segment it has systematically failed to serve — until now, imperfectly, through agreements designed to patch a gap the original model never anticipated.
The 787 to Tokyo departs whether Southwest's architecture is ready or not.