In the December–January issue, Hal Brands argues that Donald Trump is damaging the core values that constitute effective US global leadership; Erik Jones examines the threat posed to democracy by identity politics following the Catalan referendum; Richard G. Whitman discusses the potential impact of a ‘hard Brexit’ on foreign policy; Nelly Lahoud considers the future of the Islamic State as a non-territorial entity; Ian Anthony warns that abandoning the INF Treaty could lead to destabilisation; Jeffrey Lewis and Bruno Tertrais examine the response to the 2013 Syrian chemical-weapons attack and its impact on transatlantic relations; Alex Grigsby analyses the difficulties in establishing norms for cyber conflict; Morena Skalamera highlights Russia’s lasting influence in Central Asia; Elizabeth Pond asks whether efforts to end the violence in Ukraine will succeed; Russell Crandall and Erik Jones contribute review essays; Jonathan Stevenson, Hanns W. Maull and David C. Unger review new books; and John L. Harper ponders whether China’s increasing ambitions will bring about a cold war with the US.