What I don't understand about the Manning case -- and what that may say about accountability in today's Army

Speaking of nutjobs, what I don't
understand about the Manning case is where the hell his chain of command was.
The guy was clearly unstable, it would seem from the testimony. So why was he
let within 100 feet of classified information?

I did a Google search but couldn't find any indication that
his senior NCO, or his company commander, have been held accountable. I did see
a reference saying that his company commander was unaware of Manning's
behavioral issues. I don't think that ignorance is a good alibi here. At the
very least here, there is probably a good case study of commanders being asleep
at the wheel.