Europe has suffered a decade of crises, with sovereign-debt troubles leading to austerity policies that exacerbated divisions inside member states and between them. Thereafter the Union was confronted with the challenges posed by a revanchist Russia in Ukraine and by a surge in migration from the Middle East and other conflict zones. The June 2016 UK vote to leave the Union threatened further damage to an institution that acknowledges it has failed to punch its weight in the spheres of foreign, defence and security policy. While that is a chronic shortcoming, its impact is becoming more acute as economic power moves East and Europe can no longer count on the steadfast support and leadership of the United States. The costs of Europe's failure to achieve strategic coherence and effect are steadily rising. This Adelphi book addresses the consequences of Europe's multiple crises for its standing as a strategic actor, acknowledging its unique character and capabilities. It argues that strategic thought and action is belatedly being informed by the deteriorating security environment, and that nascent initiatives have the potential to effect a step-change. There are grounds for cautious optimism, visible in the success of stabilisation and counter-piracy operations as well as coordinated diplomatic activity. Also, the continent's leading powers are becoming more pragmatic about how cooperation is organised within and beyond the Union. These developments offer the possibility that Europe might meet its aspirations to be a strategic actor of consequence, despite a long-track record of disappointment and the still-considerable obstacles that lie in its path.