A pioneering examination of history, current affairs, and daily life along the Russia–China border, one of the world’s least understood and most politically charged frontiers. The border between Russia and China winds for 2,600 miles through rivers, swamps, and vast taiga forests. It’s a thin line of direct engagement, extraordinary contrasts, frequent tension, and occasional war between two of the world’s political giants. Franck Billé and Caroline Humphrey have spent years traveling through and studying this important yet forgotten region. Drawing on pioneering fieldwork, they introduce readers to the lifeways, politics, and history of one of the world’s most consequential and enigmatic borderlands. It is telling that, along a border consisting mainly of rivers, there is not a single operating passenger bridge. Two different worlds have emerged. On the Russian side, in territory seized from China in the nineteenth century, defense is prioritized over the economy, leaving dilapidated villages slumbering amid the forests. For its part, the Chinese side is heavily settled and increasingly prosperous and dynamic. Moscow worries about the imbalance, and both governments discourage citizens from interacting. But as Billé and Humphrey show, cross-border connection is a fact of life, whatever distant authorities say. There are marriages, friendships, and sexual encounters. There are joint businesses and underground deals, including no shortage of smuggling. Meanwhile some indigenous peoples, persecuted on both sides, seek to “revive” their own alternative social groupings that span the border. And Chinese towns make much of their proximity to “Europe,” building giant Russian dolls and replicas of St. Basil’s Cathedral to woo tourists. Surprising and rigorously researched, On the Edge testifies to the rich diversity of an extraordinary world haunted by history and divided by remote political decisions but connected by the ordinary imperatives of daily life.