Last week, the US Public Broadcasting System aired a 55-minute documentary detailing how President Obama repeatedly stepped back from action against Syria’s Assad regime — even after the chemical weapons attacks of August 2013 that killed up to 2,000 people near Damascus.

Most of the story is familiar, but the program pulls together the chapters: Obama’s disappearing “red line” against regime killing of civilians, the President’s abrupt choice to join Russia after the August 2013 attacks, and the shift from the Assad regime to the Islamic State as the focus for any action.

Most of the program is scathing in its criticism of Obama, to the point where the Chairman of the Joint Chief Staff, General Martin Dempsey, shows his disapproval — in body language, if not words — of his Commander-in-Chief.

However, perhaps because of the implications of the charges, the documentary hands over the last few minutes to US commentators who rationalize Obama’s failure to act.

Professor Joshua Landis, University of Oklahoma and Syria Comment: “In a sense, Washington needs Assad today. That’s the horrible truth….We are strategically allied with Assad. He is a bulwark against the spread of ISIS [the Islamic State]….If America destroyed Assad…who’s going to take Damascus? It’s going to ISIS and [Jabhat al-] Nusra.”

Andrew Bacevich, historian: “When we talk about moral obligations, there is also a moral obligation…to learn from one’s mistakes rather than insist that, if we try harder, we will get a better outcome.”

Derek Chollet, historian and Obama advisor, 2011-12: “I think it’s going to be one that historians are going to have to sort out….For anyone to look back and say there were easy choices to be made, I don’t think is being true to themselves [sic].”

Asked about Obama’s statement, “We don’t do stupid shit,” Landis responds:

Good thing….In a horrible, bleak world of this conflict, civil war in Syria, that’s not a bad motto. You do need to realize the limits of your ability.