When did the Army lose focus on personal responsibility?
We as leaders have always been responsible for our Soldier's duty performance, and not always their personal conduct. It was a gradual erosion of our leaders' ability to take responsibility in their own actions (personnaly and professionally) that caused the American public (and our leaders) to lose faith in our ability to lead that sparked this.
Case in point- A Soldier was seen sober and awake at 1230 am one night by three different leaders. When asked what his plans were, he stated "going home and to bed". at 0430 the SAME MORNING, (three hours later) he was pulled over by the State police 50 miles away and blew a .104. Whose fault was it? Not the PLT leadership, but everyone was there, from the Team leader through PLT Leader. 14 Soldiers to answer for one Soldiers' misbehavior.
The Army has always been a reactionary organization- we try to institute controls and regulations to prevent bad things from happening to our Soldiers. What is happening here is an escalation of effects, trying to control a situation that cannot be effectively controlled- Human free will.
Our Soldiers are not automations that can be turned off and on at will, and this very unpredictability is what makes us sucessful in combat and gives our leadership headaches. What is the solution? Since we live under a microscope because of our Senior leaders' inability to accept (and explain) that s**t happens, and we are all adults, it will only get worse.

