I’ve been silent for a while. I’ve been silent about Afghanistan for longer. But too many things are going unsaid. I won’t try to evoke the emotions, somehow both swirling and yet leaden: the grief, the anger, the sense of futility. Instead, as so often before, I will use my mind to shield my heart. And in the process, perhaps help you make some sense of what has happened. For those of you who don’t know me, here is my background — the perspective from which I write tonight. I covered the fall of the Taliban for NPR, making my...