In their fight against the debt crisis, the European Union and its member states took measures that have profoundly changed the euro. It now differs fundamentally from when it was introduced by the Treaty of Maastricht. Surprisingly, this change has come about with hardly any formal amendment to the Union's 'basic constitutional charter', the Treaties. How, then, to understand it? This book argues that the constitution of the EU has transformed, which occurs when constitutions change without amendment. The transformation is characterized by a broadening of the currency union's stability conception from price stability to also financial stability. Using solidarity as a lens, the book conceptualises the unity of the member states and analyses how this was preserved during the crisis. Subsequently, it explains how that changed the currency union's set-up and why the European Court of Justice could not turn against the change in Pringle and Gauweiler.

‘The Currency of Solidarity … aims to contribute to the academic analysis and debate on EU constitutional change through a set series of cumulative events that took place in Brussels, Luxembourg, and many other EU capitals in response to critical market developments when many feared the end of the European project. At times, the narrative of the book moves out of the law together, and helps the reader understand the historical and political backdrop. For ardent lawyers … this weaving in and out of the law is unnatural. Yet, this style of Borger’s writing through which a particular narrative is adopted is a considerable achievement … This is one of the most 'in context' books in EU law that has been published to date. It will be interesting to see if EU legal scholarship continues going down this path.’

Dr Graham Butler Source: European Law Review