An extra three weeks of intensive training to qualify as an underwater combat medic. Republic of Singapore Navy | Ng Eng Hen

Before they train Army recruits at basic training, drill sergeants must graduate from the nine-week United States Army Drill Sergeant Academy. Insider spent a week at Fort Jackson in Columbia, South Carolina, to see what it takes to become a drill sergeant. The Drill Sergeant Academy has adopted a new strategy where the old days of breaking down recruits with yelling and push-ups have been replaced with a more collaborative and respectful tone. Drill sergeant candidates are taught how to effecti