Precisely 20 years ago, on November 22th, 2004, the Treaty on the European Corps and the Status of its Headquarters was signed in Brussels. Twelve years after Eurocorps had been created, this treaty embodied the will of the then five Framework Nations (Germany, Belgium, Spain, France and Luxembourg - Poland would join later, on December 20th, 2021) to establish an undisputed legal basis. As a result, Eurocorps became an entity in the category of sui generis legal objects, i.e. entities whose characteristics make them unique.
Eurocorps is sui generis indeed. Firstly by its legal nature, as it is a multinational headquarters (and not an international organisation). As such, even though land-centric by design, it is also capable of joint operations. Secondly, by its purpose, as it can be placed at the disposal of the North Atlantic Treaty Organisation (NATO), the European Union (EU), the United Nations (UN), or a Framework Nation, always based on a joint decision.
The treaty also provides the headquarters with its own ecosystem. Its composition may also evolve in time: EU Member States may join the corps as full-fledged Framework Nations, as was recently the case with Poland, and any state may apply to assign personnel to Eurocorps and thus become an Associated Nation.
Apart from these legal peculiarities, the ToS provides Eurocorps’ nations with an agile and operational tool. By signing the treaty, the Framework Nations were merely confirming what they had already implemented: in 2004, right at the time when the treaty was signed, a large part of Lieutenant General Py’s staff and its integrated support were on operational commitment in Afghanistan, leading the International Security Assistance Force (ISAF).