He says Pyongyang halted contact between the Red Cross delegations in the truce village,Panmunjom, and the North Korean Navy contacted the South to inform it that all marine communications between the two Korea's are now cut.
VOA: standard.2010.05.26
There was a brief thaw in relations when the Cold War ended, because with the RedNavy gone the U.S. Navy needed to highlight its relevance to fighting ashore, but the more common pattern is for the Navy to constantly question the requirement for Marine assets like vertical-takeoff jets and maritime prepositioning ships (which store warfighting supplies in likely areas of conflict).