Globalization means that the domestic policies of one country can influence the welfare of other countries. This interdependence affects an ever-widening range of regulatory matters in areas such as environmental protection, macroeconomic policy, and individual rights. As compared to the security conflicts and tariff disputes of centuries past, today’s regulatory fights mobilize a broader range of domestic bureaucracies, civil society groups, and other political actors—some with the ability to form political alliances across borders. In this brief book, two scholars examine a recent series of such disputes between the United States and its European partners over coordinating transnational flows of information about airline passengers, bank accounts, and commercial transactions. In general, the United States sought more access to data for the government and private firms, whereas the European countries favored more individual protections. The authors show that negotiations over these issues, both within and across nations, tend to be complex and fraught, not least because they pit intense commercial and security interests against deep-seated norms of individual privacy. When it is expedient, groups representing these interests have mobilized internationally. The book shows how government officials, nongovernmental organizations, and legislators reached across borders in this way. Yet it remains unclear what effect transnational activity had on the ultimate policies the United States and Europe chose, which have generally tracked relative power and interests.