When Chaiwat Kovavisarach first stepped into Bangchak Corporation Plc in the early 2000s, the Thai oil refiner was fighting for survival. The aftershocks of the 1997 Asian financial crisis were still reverberating through Thailand’s economy. Bangchak, then a small, state-linked refinery under the Ministry of Finance, was burdened with debt and on the verge of shutting down. Several global banks had attempted to stabilise it without success. Chaiwat, then an investment banker running his own...