South Asia’s economic potential has long been constrained by low levels of economic integration. Despite being closely linked geographically, culturally and historically, intra-regional trade is very low. A major problem has, of course, been political difficulties within and between South Asian countries. But an important, and overlooked, barrier to greater economic integration is the poor quality and inadequate investment in infrastructure in the region. The newly established Asian Infrastructure Investment Bank (AIIB) can play a pivotal role in fixing this problem.