SEOUL, Aug. 24 -- The South Korean Marine Corps had been planning the Ssangyong exercise for months. The landing craft formations, the combined amphibious assault drills, the command and control rehearsals that define what two nations can actually do together when they need to put soldiers on a beach - all of it built around the assumption that American Marine forces would show up. They will not. Washington has informed Seoul that the Iran war has consumed the deployment capacity the exercise requires.

The cancellation of Ssangyong - the biennial flagship combined amphibious landing drill that has anchored US-South Korea military readiness - was formally communicated to the South Korean military in June, Al Jazeera reported Monday. Han S...