People often ask me about Australia. It doesn’t matter where I happen to be. There seems to be no end of interest in the massive but tiny country that Paul Keating once memorably described as ‘the arse-end of the earth’. Over the eight years that I have been working as a foreign correspondent, however, I have noticed the nature of the questions changing. They have become more political, lined with disappointment at best and subtle condemnation at worst.

It was in the canteen car of the late-night service that the Vietnam veteran finally told me his story. We’d been friends for months, regulars at a Louisiana-themed bar off Saigon’s Bùi Viện backpacker strip, but his time in-country was, if not exactly taboo, not really a go-to topic, either. The story that unfolded was right out of Michael Herr’s Dispatches, an un-filmed sequence of Apocalypse Now conveyed orally, in equal parts surreal and evil. What surprised me was how unsurprised I was by it all.

What they are waiting for is el tren, the now infamous freight service that takes them to Ixtepec, Oaxaca, and on into the cartel-controlled state of Veracruz. There, many are beaten, sexually assaulted, robbed, extorted, kidnapped or killed – and there are few, if any, lucky ones.