Two flag carriers that have been quietly cooperating since the early 1960s signed a new agreement in Seoul on 3 September. On its own that would barely register. The timing is what makes it interesting.

In fourteen weeks, Asiana Airlines ceases to exist. On 17 December its name, its logo, its 240 aircraft, its staff and its route network all disappear into Korean Air. Japan Airlines has just made sure it is standing in the right place when that happens.

The deal itself

The substance, as reported by aeroTELEGRAPH and FlightGlobal, is deliberately open-ended. The two carriers will review their codeshare and loyalty cooperation and progressively adapt it to Korean Air’s larger network. They also plan to work together in new areas, including projects aimed at improving sustainability in aviation.

What is notable is what it is not. This is not a joint venture, not an alliance switch, and not an equity stake. JAL remains in Oneworld. Korean Air remains in SkyTeam. It is two airlines from rival alliances agreeing to work more closely because the commercial logic across the Sea of Japan is stronger than the alliance logic.

What is actually happening in December

The Korean Air-Asiana merger has been grinding forward since November 2020, when Korean Air announced a government-backed rescue of its stricken rival. Hanjin Group took a 64 percent stake in December 2024, but the two airlines carried on operating largely separately for another eighteen months.

That ends on 17 December. One brand, one operating certificate, one loyalty programme — Asiana Club is absorbed into SKYPASS, with flight-earned miles converting one for one.

For Star Alliance frequent flyers it is straightforwardly bad news. Asiana has long been one of the better transpacific business-class redemptions available to United MileagePlus and Aeroplan members, and those bookings stop being available.

For SkyTeam members, and particularly Delta, it is the opposite. Asiana’s transpacific flights move into the Delta-Korean Air joint venture, and Delta passengers gain access to Asiana’s Asian network on a single booking out of Incheon.

Why JAL wants a seat at this table

Japan and South Korea between them generate one of the densest short-haul international markets on earth, and both Seoul-Incheon and Tokyo-Haneda function as long-haul gateways for the region. When one of the two Korean flag carriers absorbs the other, everything about how traffic flows between the two countries gets renegotiated.

JAL has chosen to renegotiate before the merger rather than after it. That is not glamorous, but it is the sort of decision that determines who gets the connecting passenger in 2028.

The Korean Air-Asiana merger, explained ahead of the 17 December integration date.

The competition question

Regulators worldwide spent years worrying about exactly this. To get approval, Korean Air agreed to give up slots and traffic rights on 34 international and domestic routes — handing Incheon to London Heathrow to Virgin Atlantic, and Incheon to Los Angeles, San Francisco and Honolulu to the small Korean carrier Air Premia.

Whether that works is doubtful. Air Premia has nine aircraft, no traditional business class, and has already cut frequencies on its Los Angeles service. On the routes that matter most, the merged Korean Air will face considerably less pressure than Asiana used to apply.

Which is, in the end, why JAL signed. A bigger, less-constrained Korean Air is a more valuable partner — and a more dangerous competitor to be outside of.

Sources: aeroTELEGRAPH, FlightGlobal, Business Traveller, Korean Air, Japan Airlines.