Bangladesh, June 20 -- In the shadows of Myanmars prolonged civil war, a quiet but profound shift has taken place in Rakhine State – one that may hold the key to solving one of the most protracted refugee crises in the world. As traditional diplomatic avenues have collapsed and global attention wanes, a new and surprising actor has emerged at the center of repatriation prospects for the Rohingya: the Arakan Army.

For years, the Rohingya – a persecuted Muslim minority driven out of their homeland in waves of violent purges, most notably in 2017 – have lived in a state of limbo. Nearly one million remain in refugee camps across the border in Bangladesh, where hope is in dwindling supply and the living conditions worsen by...