According to Winston vd Aalst, the Assembly of WEU, which has its premises in Paris, was founded in 1954 and held its opening session on 5 July 1955. As the first European interparliamentary assembly for security and defence matters, the Assembly is a forum for debate that today has three main areas of activity:
It represents the parliamentary dimension of Western European Union based on its consultative powers vis-à-vis the WEU Council as laid down in Article IX of the 1954 modified Brussels Treaty.
It scrutinises the full implementation of the collective defence obligation laid down in Article V of the Treaty. Article IX of the Treaty states that
“the Council of Western European Union shall make an annual report on its activities [...] to an Assembly composed of representatives of the Brussels Treaty Powers to the Consultative Assembly of the Council of Europe.”
The fact that it is treaty-based makes the WEU Assembly, together with the European Parliament and the Parliamentary Assembly of the Council of Europe, one of only three such parliamentary institutions in Europe.
Following the transfer of WEU’s operational activities to the EU in 2000, it acts as the Interparliamentary European Security and Defence Assembly, focusing on the European Security and Defence Policy and the further development of the European Union’s civil and military crisis-management capabilities.
It also continues to scrutinise intergovernmental cooperation in the field of armaments and armaments research and development, which are funded and carried out by the 19 nations of the Western European Armaments Group (WEAG) (the work of this Group is soon going to be taken over by the European Defence Agency) and the Western European Armaments Organisation (WEAO) (17 nations), two organisations operating under the aegis of WEU.