Bangladesh, Aug. 19 -- The ink is barely dry on the ceasefire agreement between Thailand and Cambodia, and yet the situation on their contested frontier remains fraught with tension. Thailand — still shaken by rumors of a looming military coup — remains a key US ally. Cambodia, in turn, leans heavily on Beijing for military aid and strategic backing. This has turned what would otherwise be a localized border skirmish into a vivid microcosm of the Second Cold War, complete with proxy alignments, diplomatic maneuvering, and strategic signaling.

The July clashes, some of the fiercest in years, left dozens dead and displaced communities along the border. The territorial disputes — rooted, as they are, in old maps, colonial ...