Naval Construction Battalions were conceived of as replacements for civilian construction companies in combat zones after the attack on Pearl Harbor. At the time civilian contractors had roughly 70,000 men working U.S.N. contracts overseas. International law made it illegal for civilian workers to resist an attack. Doing so would classify them as guerrillas and could lead to summary execution. That is exactly what happened at Wake and would serve as the backstory to the World War II movie "The Fighting Seabees".