Just a cursory look, but it seems like PBS puts most of the blame on the Bush Administration.
- "If only they had responded to Iranian moderates' conciliatory overtures."
- "If only democratization had succeeded in Afghanistan and Iraq."
- "If only we had reached an agreement on quelling the insurgency in Iraq."
- "If only Bush hadn't slapped Iran in the face by putting them on the Axis of Evil list."
And so on.