I grow weary of sounding the death knell of the U.S.-Korea alliance now that it’s just a question of being how fast and how ugly. If anyone is smart and honest enough to offer a cogent defense of it, it’s U.S. Ambassador Alexander Vershbow, who has made plenty of enemies in Korea by speaking his country’s views plainly. Now we know that the best justification he can offer is as light, flavorless, and indigestable as styrofoam, and just as easily...