Under this plan, the European Union pledged itself during the Helsinki summit to be able to deploy rapidly and then sustain forces capable of the full range of Petersberg tasks (as set out in the Amsterdam Treaty), including the most demanding, in operations up to corps level (up to 15 brigades or 50,000-60,000 persons)[1][2] to be capable of intervening in any crisis that could occur in an area where European interests are affected.[4] The aim was to make those forces self-reliant, able to deploy within 60 days and over 4,000 km (2,485 mi), and sustainable in the field for a year. This means the force would actually have to number around 180,000 troops so as to provide rotating replacements for the initial forces.