What “The Zygon Inversion” suggests, however, is that the vast majority of wars are fought not between good and evil but rather between opposing groups too overwhelmed by petty hatred and fear to recognize what the Doctor points out, that war only delays the inevitable moment in which the two sides sit down and actually talk through their differences. Of course, by then, that fundamentally unnecessary war has likely already created all the trauma and anguish necessary to breed the next generation of warmakers.

Stripping war of the delusional glory and sense of self-righteousness imparted by actual combat and reducing it all to the mere push of a button—more than that, refusing to grant war unearned solemnity by treating it as anything other than a sick, destructive game—allows the Doctor to get through to two scared, angry people who sincerely believe they have no alternative. Here again we see what is so powerful about Capaldi’s Doctor compared with his predecessors, as his emotional straightforwardness gives his speechifying an immediacy and a vulnerability that might have eluded the 10th or 11th Doctors. While the Doctor remains fundamental to the resolution here, the story isn’t all about him, as evidenced by his utter refusal to engage with Zygella’s argument that the current situation is somehow his fault. The Doctor created the possibility of peace, and he left it to humans and Zygons alike to make the right choices within that framework.

While last week’s “The Zygon Invasion” drew plenty of parallels with modern-day extremist groups, the Doctor’s grand appeal ends up universalizing the issues under discussion. It’s perhaps a little corny to hear the Doctor use the words “cruel” and “cruelty” quite so many times in a row to describe the cycle of war, but it’s corny in a way that’s very true to Doctor Who, and it’s not as though the Doctor is wrong in his assessment. Again, the arguments put forth in “The Zygon Inversion” are nakedly idealistic, but if the Doctor isn’t going to take a stand for the value of naked idealism, then who the hell is? What makes this work is that the Doctor gradually drops the high-and-mighty act, growing ever more desperate to get through to Zygella. This is a Doctor who is not too proud to plead and beg, and he points out that he speaks against war not in the abstract but from the most terrible of earned experience. We’ve seen the Doctor articulate his Time War trauma before, and Capaldi’s anguish here as he describes how the memories of his atrocities will never, ever leave him is as powerful a statement as any the new series has ever produced. There’s also that final moment, as he at last reaches Zygella, as his expressions run the emotional gamut. The Doctor has never looked quite so old, so worn down by the pain he carries, yet his defiance endures.

Doctor Who: The Zygon Inversion – AV Club

Coleman’s performance as Bonnie is nicely textured, shifting between pragmatic commander and zealous true believer. That’s all consistent with the idea that Zygella acts not so much out of some coherent if extreme philosophy as she does in angry, hurt reaction to perceived injustices. The world has hit her, and she wants to hit back, hard. All her actions make grimly perfect sense within that framework…

The other thing that puts this episode in conversation with “The Day Of The Doctor” is the explicit link the Doctor makes between Bonnie’s decision to not use the Osgood box and his own choice to not use the Moment and to save Gallifrey. More broadly, tonight’s episode serves to clarify a message that earlier story attempted to convey amid all the 50th anniversary spectacle: War requires making hard choices, but the hardest choice of all can be deciding to fight for peace. That choice is difficult not because it requires terrible sacrifice or grim resolve, but rather because it requires a person to look deep within themselves and to put aside their own pettiness, to find the capacity to forgive and to let go of their grievances. “The Zygon Inversion” brings it all down to a pair of boxes, each with a pair of buttons. The simplicity of that setup allows this two-parter to be one of the show’s strongest ever statements against war, not because the Doctor is challenging us from on high to live up to his standard, but rather because he wants no one else to know his pain. He’s already had more than enough truth and more than enough consequences to last him infinite lifetimes.

(via inandoutofcars)