A frontier of potential trade is constructed for trade flows from a world trade matrix of trade determinants to compare East Asian trade performance with that of South Asia. The results suggest that East Asian trade, led by ASEAN, is outperforming the world while South Asia lags behind significantly. Within East Asia, the transformation of China’s trade performance is remarkable with its accession to the WTO. Australia is efficiently integrated with East Asia and performing close to its trade frontier. There is scope to lift intraregional trade among the East Asian economies but South Asia has even more unrealised potential, including within its own region.