This week sees the UN forces execute Operation Chromite, the amphibious invasion of the port of Incheon, far behind enemy lines. There are many hurdles to clear before this can happen, including the physical one of one of the world's largest tidal ranges, which leaves many kilometers of mud flats in the approaches. There is also a UN counterattack at the same time, designed to perhaps break out of the Pusan Perimeter, or at least tie down big chunks of the enemy in the south.