A United States Army drill instructor is an experienced soldier, usually a career non-commissioned officer, whose job it is to train new recruits in the basics of army life and the army's mission. A person in this position should technically be called a "drill sergeant," since only the US Marine Corps uses the title "drill instructor." While the title implies the basics of protocol, drill and ceremonies, such as marching, saluting, executing the manual of arms and other practices and customs of military life, the army drill instructor is also responsible for training recruits as combat soldiers, so that regardless of their actual job in the army, they'll always be ready to defend themselves and their comrades.
Indoctrinating a new recruit into the military lifestyle is a critical assignment. All military services expect to be able to function as a highly efficient team, responding without delay or question to orders whose underlying logic or strategic importance often cannot be shared with the team. Recruits must be able to fit into this team. Many of the routines and exercises they go through during their period of basic training are designed to break down the recruits' sense of self and selfishness, replacing them with a sense of obedience, fraternity and selflessness. Of all the personnel involved in training the new recruit, the army drill instructor is the single most important, often determining a recruit's success or failure.
Army drill instructors usually volunteer for the position, although some are selected by the Army based on their records. They undergo a rigorous training course, covering the same material that's taught to new recruits, and also including material on training and leadership. Like a US Marine drill instructor, the Army drill instructor wears the round brown campaign hat, commonly known as the Smokey the Bear hat. Upon graduation from drill instructor school, most new drill sergeants' first assignment will be to command companies of recruits who failed their initial physical fitness test and have been assigned to Fitness Training Company, or “Fat Camp.”
New Army recruits are immediately organized into training units for basic training, or boot camp, which consists of a nine-week course in Basic Combat Training (BCT), followed by advanced individual training (AIT) in the recruit's assigned military occupation specialty (MOS). Each recruit platoon, consisting of about 40 recruits, has assigned to it a drill sergeant who will work and live with the platoon full time for the duration of their BCT, and sometimes AIT as well. The role of the army drill instructor will vary during this period. In the earliest phase of training, recruits are constantly monitored and corrected, but as the training progresses and recruits develop skill and self-confidence, they're given more freedom and subjected to less control and monitoring.
The drill sergeant commanding the platoon is responsible for overseeing all aspects of recruit training and monitoring progress with the company commander. In addition, it's the drill sergeant who will be responsible for teaching the recruits all aspects of drill and ceremonies, such as issues of protocol in the army like marching, conduct with non-commissioned and commissioned officers, treatment of the flag, the uniform, customs and practices of the service, etc. In addition, the drill sergeant will train the unit in small unit tactics and lead physical training, usually assisted by additional army drill instructors.
When training in a topic requires a high degree of proficiency, such as certain individual weapons, hand-to-hand combat or map reading, an expert army drill instructor will usually be assigned to teach these topics. Such skills as marksmanship are usually taught by teams of instructors, with the drill sergeant commanding the platoon and the marksmanship instructor commanding the marksmanship facility. Finally, recruits are taught the Army's core values of loyalty, duty, respect, selfless service, honor, integrity, and personal courage, both in classroom settings and in barracks by the drill sergeant.
An Army drill instructor's tour of duty is a significant milepost in a non-commissioned officer's career, and will generally last two years. Those who successfully complete such a tour can count on being assigned to positions of significantly greater responsibility and prestige.