Cross-border infrastructure is the next frontier for the economic integration of the Indo-Pacific. As liberalization has driven down regulatory barriers to trade and investment, today it is physical linkages-the road, rail, shipping, energy, and telecommunications connection between economies–which are the principal challenge for regional integration. Indeed, the Indo-Pacific is plagued by a range of ‘infrastructure gaps’, which have arisen as governments have struggled to supply infrastructure at the pace and quality required by their high-speed growth. Estimates suggest that $1.5 trillion of new investment per year, every year, will be required to unlock the region’s developmental potential. Building better infrastructure within and between economies is a top priority for all governments in the Indo-Pacific.