Few military units have sparked as much controversy as Red Cell. Created by Richard Marcinko, the legendary founder of SEAL Team Six, this unusual unit was tasked with exposing weaknesses in U.S.

Richard “Dick” Marcinko, the first commanding officer of Navy SEAL Team 6, the group of highly trained warriors that killed Osama bin Laden in 2011, died on Christmas Day at the age of 81, according ...