The Line Becomes a River, by Francisco Cantú (Bodley Head, £14.99)

Review by Richard Strachan

In the Age of Trump, where migrants and refugees are routinely demonised, and where the US president’s offer to build a wall along the Mexican-American border was a key part of his election-winning strategy, Francisco Cantú's stark and troubling memoir could not be more timely.

A third-generation Mexican-American, Cantú decided to bolster his International Relations degree with some on-the-ground experience and joined the US Border Patrol in 2008. ‘I’m sick of reading about the border in books’ he tells his mother, who is concerned at his choice of career. ‘Imagine what I’ll learn - imagine the perspective I’ll gain.’ What starts as an academic exercise quickly becomes more troubling though, as Cantú is exposed to the realities of the border itself; that amorphous thing, both rigidly enforced and remarkably porous. Patrolling the Sonoran desert, Cantú picks up exhausted migrants defeated by the punishing heat, assisting his colleagues as they destroy food and water stashes that could prove the difference between life and death. He helps chase down drug smugglers from the Mexican cartels, and at other times processes men, women and children for deportation, aware that only the smallest accident of history separates him from these ragged survivors of the crossing. Increasingly troubled by his work, Cantú begins to experience bizarre dreams where his teeth crumble in his mouth, and he becomes paranoid that the narcos have his house under surveillance. What started out as an adventure has become something morally and physically exhausting instead, but it’s only when Cantú transfers to an intelligence unit in Tucson, Arizona that the full weight of the border begins to crush him. Although the work is physically safer, being exposed to the full and spectacular savagery of the cartels starts to undo him completely, and in 2012, on the cusp of a psychological breakdown, Cantú quits. At this point, the memoir changes gear to become (if that’s possible) an even greater indictment of the border’s arbitrary force. Studying for a postgraduate writing degree and taking a job in a coffee house, Cantú befriends a local handyman, José, who quizzes him earnestly about his days in la migra. As he soon discovers though, his friend’s precarious position in the United States means he is about to feel the full force of the system Cantú spent four years of his life enforcing; a system devoid of nuance, combining pitiless unsentimentality with bureaucratic incompetence.

The progress of Cantú’s disillusionment with his job and of the psychological toll it takes on him is expertly portrayed. With laconic immediacy and earned reflection, he details the boredom and routine of front-line law enforcement, as well as its moments of real horror. The accounts of his awful dreams cut through the story like shards of ice, and these weird narratives of violence and decay show the extent to which the relentlessness of the job infiltrates his everyday life, giving him no peace even when he’s asleep. More than just the account of a privileged witness though, The Line Becomes a River is also a reflection on the nature and history of the border between these two countries, and by extension of state borders everywhere. Threaded throughout the book is the story of how the border came to be, and how something portrayed in a hostile media as eternal and inviolable was the result of very specific historical processes, as well as of the individual choices of those in power.

First formally established in 1848 after the Mexican-American War, the border was subject to many periods of revision in the years that followed, the boundary line being marked only by regularly placed monuments and marker stones. After various treaties, conventions and commissions, what was effectively no more than a line on a map has gradually become more tangible; a physical presence on the earth that seems entirely arbitrary to the people who live in its shadow. Eventually, the line of the border merges with the passage of the Rio Grande, where the earlier surveyors had noted that the great alluvial force of the river was regularly changing its exact position. ‘It was as if the surveyors wished to acknowledge,’ Cantú writes, ‘how the border, no matter how painstakingly fixed upon the land, could go on to endlessly change its course with the whims of a river.’

Although Cantú occasionally betrays his creative writing MFA roots in his clipped, Carveresque prose, this is a well-written piece of work, brave and necessary, and bringing a painfully honest voice into an increasingly polarised conversation.