The proliferation of "minilateral" summits is reshaping how international security problems are addressed, yet these summits remain a poorly understood phenomenon. In this groundbreaking work, Kjell Engelbrekt contrasts the most important minilateral summits -- the G7 (formerly G8) and G20 -- with the older and more formal UN Security Council to assess where the diplomacy of international security is taking place and whether these institutions complement or compete with each other. Engelbrekt's research in primary-source documents of the G7, G8, G20, and UN Security Council provides unique insight into how these institutions deliberate on three policy areas: conflict management, counterterrorism cooperation, and climate change mitigation. Relatively informal and flexible, GX diplomacy invites more countries to take a seat at the table and allows nontraditional security threats to be placed on the agenda. Engelbrekt concludes, however, that there is a continuing need for institutions like the UN to address traditional security problems.High-Table Diplomacy will provoke discussion and further research on the role of minilateral summits among scholars of international relations, security studies, and international organizations.