Delta already inherited Japan routes from Northwest Airlines in the merger.
The only reason I can see for the agreement with JAL is to monopolize the pacific routes and freeze out American Airlines.
The airlines are playing hardcore.
Not only the airlines:
The largest airline in Asia was declared bankrupt in January and is struggling to rebuild its finances and image - which it fears will be tarnished even further if its stewardesses’ sought-after uniforms get onto the black market.
The outfits, early versions of which were designed by Hanae Mori, are incredibly popular among fans with a uniform fetish and can command exorbitant prices on on-line auction sites.