When I first enlisted in the military in 1986, I went through Army boot camp and the Drill Sergeants were very strict and all business all the time. They would single you out for disciplinary measures or ass chewings without hesitation. They were fair but firm in how they dealt with the troops. I’ve heard that they can no longer single individuals out but must deal with a platoon or a squad as a whole.
After leaving the Army, I re-enlisted but this time in the Air National Guard (Air Force). I didn’t have to repeat boot camp for the Air Force since I had it in the Army but I did have to attend technical school at Lackland Air Force Base. When I was there, I was able to witness some of the activities of the Military Training Instructors (MTI is such a weird and overblown description) along with my instructors at technical school. I have to tell you that the behavior and standards of the Air Force is so mellow and relaxed compared to Army standards that I’ve often thought that the Air Force may not be adequately preparing young Airmen for a career in the Air Force, let alone the military but that is only my opinion based on my observations. I don’t regret any of the training that I’ve ever been offered by the Air Force and I was sincerely happy with my transition from the Army to the Air Force since I believe that the AF takes better care of their people. They probably just need to be more stringent and serious in their basic training methods.
With that said, they do follow the cirriculum set forth by Air Force standards but it is much easier than what you would find in the Army and Marines. I had a friend and also my younger brother who were both in the Navy for a number of years but they never told me what the basic training instructors were like or what the boot camp standards entailed. I’m also unsure about anything involving the Coast Guard also.