This book contributes to an ongoing debate about the EU as a global actor, the organization's ability to speak with one voice in energy affairs, and the external dimension of the regulatory state. Investigating whether the Energy Union amounts to a fundamental shift towards Europe's new 'Liberal Mercantilism', it gathers high-level contributors from academia and the policy world to shed light on the changing nature of the EU's use of power in one of its most crucial policy fields. It argues that the Energy Union epitomizes a change in the EU's approach to managing its economic power. Whilst the EU remains committed to a liberal approach to international political economy, it seems ready to promote regulation for the purpose of augmenting its own power at the expense of others, notably Russia. This edited collection will appeal to political scientists, economists and energy experts.