The Brigade comprised a number of troops varying between four and five thousand, drawn from units pledged by eleven countries: Argentina, Austria, Canada, Denmark, Finland, Italy, the Netherlands, Norway, Poland, Romania, Spain and Sweden. The nations that contributed to SHIRBRIG had the right to opt out of any operation. For example, when the UNMEE was formed, Argentina and Romania opted out for financial reasons. Establishment of a standing U.N. volunteer peacekeeping force represents a key goal of most world federalists.