Book description, from the publisher’s website:
After Todd Barbery, director of a humanitarian organization working with refugees, is assaulted and kidnapped on the streets of Kabul, Afghanistan nothing remains the same. How could it? 

What Changes Everything is the story of Todd’s wife, Clarissa, who tries to save her husband, while her own life spins out of control in the dark nights of Brooklyn. There on the night streets, she meets Danil, an angry New York graffiti artist whose life was derailed by a loss in the same incomprehensible war half a world away. Danil’s mother Stela writes letter after letter from her bookstore in Cleveland in hopes of comprehending the loss of one son on an Afghan battlefield and of reconnecting with Danil, who abandoned her in anger when his brother died. This is also the story of Mandy, a mother from Texas, grappling with the fury of a wounded son who barely made it home from that war. And it’s Todd’s story, too, who for only a moment let down his guard in a Kabul marketplace and now confronts the worst of possibilities. 

But, remarkably, What Changes Everything also tells another story: the true story of Mohammad Najibullah, the last president of Afghanistan during the Communist era, whose fall from power was made final by the arrival of the Taliban. The letters in this novel from Najibullah to his three daughters are imagined, but the author had the privilege of lengthy exchanges with one of them, who shared recollections of her father—and a poem her mother had written about him. 

Masha Hamilton braids the lives of all these characters, real and imagined, into a powerful novel about the grace of human connections in a world that is so often too harsh and dangerous to face alone,

Comments: As she shifts between the perspectives of half a dozen characters, Masha Hamilton explores geopolitical conflict through the individual experiences of a kidnapped relief worker and his wife, two soldiers and their families, and a deposed political leader refusing to be exiled from his native land. That land, and the common bond between these characters, is Afghanistan, and what happens there is What Changes Everything.

While the common thread of the novel is Afghanistan, its connective tissue is the character Amir. The five sections of What Changes Everything are each framed by a fictional letter from Afghanistan’s last Communist leader, Mohammad Najibullah, to his wife and daughters. When he was brought down by the rising power of the Taliban, his family fled into exile in India. Afforded protection by the United Nations, Najib is aided by the young Amir, who works behind the scenes to broker his release to join his family, although Najib resists leaving their country behind. Years later, Amin finds himself in a similar role when his boss, American humanitarian worker Todd Barbery, is kidnapped from the streets of Kabul by Islamist terrorists. At home in New York City, Todd’s wife Clarissa and daughter Ruby disagree over the appropriate intervention to obtain his release, and in the midst of this conflict, Clarissa crosses paths with Danil, a Russian-born street artist whose work is informed by the loss of his soldier brother to friendly fire in Afghanistan.

Hamilton reinforces the parallels between the captivity stories of Todd and Najib by employing Amir in both of them, and explores the complexity of modern-day Afghanistan–a country that once sought to be truly “modern,” but now struggles against what that signifies–through these characters’ connections with people outside it. The changes that truly change everything, more often than not, are those that happen person to person. What Changes Everything wraps a tense, fast-moving plot around the effects of these changes.