At the European Union's Helsinki summit of December 1999, European leaders took a decisive step toward the development of a new Common European Security and Defense Policy aimed at giving the EU a stronger role in international affairs backed by a credible military force. This Marshall Center Paper analyzes the processes leading to Helsinki by examining why and how this new European consensus on defense issues came about. It takes the pulse of the EU's emerging defense policy and touches upon the main controversies and challenges that still lie ahead.