Book excerpt: Open Regionalism is regional economic co-operation without discrimination against countries outside the region. The concept grew from the experience of rapid growth, and expanding trade and investment across national borders, in East Asia and the Pacific. It became the guiding idea of Asia-Pacific Economic Co-operation. It is now recognized as being the means through which the growing appeal of regional trading arrangements can be reconciled with a flourishing global trade system within the framework of the new World Trade Organization.