Near the heavily fortified frontier dividing the Korean peninsula, the abandoned Woljeong-ri station is being recast as a symbol of South Korea’s hopes to reconcile with the North. But plans to reconnect South Korea’s northernmost station to the rail network come at an awkward moment, as Pyongyang ignores Seoul’s overtures while the South’s old ally Washington pursues its own talks with Pyongyang. A turbulent few days have raised doubts about the role of South Korea in any diplomatic push,...