Sanctions have brushed up against shipping again — this time as the US and UK impose further measures against the Myanmar military regime, after a coup in February.

Both countries blacklisted Myanma Economic Holdings Ltd (MEHL), one of two highly-diversified and allegedly military-backed companies that the current regime uses to enrich itself and maintain power.

MEHL — which the US describes as a "vast and secretive" conglomerate — has...