Early one morning in late September, the hum of a metal detector fills the air in a sparse field. A man in a plastic face shield and blue armored vest is crouched near the ground, scanning the wand over a meter-wide lane. He carefully marks the clear path with red-painted sticks: Inside is safe, outside is potentially deadly. He works in a former battlefield in a remote corner of southeastern Angola where rebel troops staged their final clashes at the end of a civil war nearly two decades ago. Today, it’s a heavily mined national park. Peering over the de-miner’s shoulder is Prince Harry, the Duke of Sussex.

Angola, which spans nearly half a million square miles along Africa’s west coast,