Where did the term S2 originate in reference to military intelligence officers?

Answer 1

There were traditionally four staff officers at a battalion or a brigade. The S1 officer is in charge of personnel. He or she is also called the Adjutant. The S2 officer is in charge of intelligence and security. Most of the S2 shops I've been in maintained the battalion's map collection. S3 is in charge of four things: operations, training, air operations and ammunition supply. In peacetime, the S3 officer is in charge of operations and training, a pilot is the S3 Air officer and a sergeant gets the job of ammo supply NCO. In wartime a training officer is assigned because operations suddenly becomes a job for about six people. In reality, an ammo supply officer should also be assigned but they don't because, by the time you get into a situation where people are shooting back at you, the sergeant has become really good at ammunition supply. The S4 officer is in charge of all supplies except for ammunition. Unfortunately for the Army, a lot of battalion commanders take a second lieutenant whose Officer Evaluation Report doesn't look too good and make him S4 so he won't contaminate the troops. It's unfortunate that he does this because the S4 function is crucially important to the success of the unit. Other battalion commanders take their best supply sergeant and make him S4. These commanders will designate the S3 the "S3/S4" just so an officer will be available to sign forms. Occasionally you'll find a really kick-ass colonel who understands how badly a poor S4 can hurt his unit, and he'll pick a really good officer to be the S4. You don't find colonels like this very often, and when you do you take very good care of them. How did it get this way? No one really knows; it just kinda happened.