If the Trump administration adopts the economic protectionism that the U.S. president threatened to pursue during his 2016 campaign, the countries of Latin America could respond with “open regionalism”—bringing their economies closer together while deepening their integration into other inviting global markets. Although crafted prior to the U.S. election, the message of this volume by World Bank economists is even more pertinent today. It offers a warning to those who imagine that Latin America has no alternative to U.S. markets and so can be readily bullied into unilateral trade concessions. The authors recognize that advocates of open regionalism—hardly a new concept—have failed to raise intra-regional exports beyond 20 percent of total exports. But a cold shoulder from the Trump administration might act as a catalyst. The authors recommend further trade liberalization, especially between Mexico and countries in Central and South America, and argue that the region’s governments should harmonize their countries’ rules and regulations, expand their investments in regional infrastructure and logistics, and, most controversial, remove barriers to the migration of workers across national borders.