Abstract

The Solidarity Clause constitutes one of the most relevant tools of the European Union legal framework on major crises management. Created by the Treaty of Lisbon, the Clause is considered to be a nice example of the advantages provided by cooperation among the EU and its Member States in so far as it is meant to guarantee an adequate division of the tasks and duties between both types of agents. However, its real utility is yet to be checked, since it has never been invoked. Therefore, some important issues related to the Clause remain still unclear, such as the concrete sense of the term “solidarity”, its relationship with the Mutual Defence Clause, the level of intensity that a crisis should reach to allow activation of the mechanism, the consequences of a violation of the Clause, etc. This chapter is intended to bring some light to these challenging issues through a careful analysis of the Solidarity Clause.