I didn't know why, but I cut through and took a shorter route and I happened to bump into my battle buddy (SSG). As I piece everything together, I remembered my battle buddy telling me that I was scaring him, because I had “that look”

You don't do anything without your battle buddy. If your battle buddy does something stupid, you pay for it.

To teach you this lesson, your Drill Sergeants will assign you a battle buddy.

In fact, the system works so well that the Army has expanded the battle buddy system to units other than basic training

Battle buddy

Meaning

Noun