Story about this - I joined the Marines in 2009. The Surge was still in full effect. It pushed a huge number of boots through the training pipeline, and the training schools were not ready for it.

Before the Surge, upon arriving to training school, you'd be stuck on what was called Barracks Support for a week or so. This was literally nothing but janitorial work - you formed up for roll call at 7:30 in the morning, cleaned until noon, formed up again to go to lunch, formed up again from lunch at 12:45, and then cleaned until 5:00 in the evening. It was an exercise in pretending to stay busy - after all, the barracks were getting cleaned by 45+ Marines 5 days a week for 8 hours a day, so the place was utterly spotless to begin with. If you were spotted goofing off, you got screamed at and punished.

Of course, there was a caveat... if you smoked, you could just sit in the smoke pit all day and not have to even pretend to be busy. Since you didn't have anything else to spend your money on, most people viewed the three packs of cigarettes as being a perfectly good cost to avoid getting fucked with for eight hours a day.

Normally, this wouldn't be too bad, as most people were stuck on Barracks Support for a week or so. However, the Surge threw this all to hell - suddenly, you had people who were stuck in this limbo for months.

Of the 120 people I went through the pipeline with, more than 75 of them got addicted during that 2-3 month period. Most of them didn't quit for years, and plenty of them are still smoking.