Every few years, the winds that bind Southeast Asia together carry something unwelcome: smoke from fires burning across Sumatra and Kalimantan, drifting across borders until it settles over Singapore's skyline. On Saturday, that ancient pattern reasserted itself, with the city-state's central region enduring more than a day of unhealthy air while the west briefly joined it before recovering. It is a reminder that geography and climate do not observe sovereignty, and that the choices made on distant islands — about land, fire, and dry seasons — arrive, eventually, as the air that five million p