Since the Libya War in 2011 it has been widely suggested that NATO's role in US security policy has diminished, because Washington gives Europe less and Asia more strategic priority (a tendency that is reinforced by budget restraints), and because the US is no longer interested in always leading NATO activities that mainly concern European conditions. Several experts have suggested that the US expect that the European security challenges primarily should be handled by NATO's European allies in a new transatlantic burden sharing model, and that the US role should principally be Article V-focused. This book investigates to what extent these claims are valid, and what consequences they may have for European and international security.