The novel Rainbow Six describes Rainbow as an international counter-terrorism operation hosted by NATO and funded by money funneled through the U.S. Department of the Interior.
The base of operations for Rainbow is located in Hereford (home to SAS), due to the United Kingdom being one of the most accessible countries in the world and also due to the press constraints that would not be possible to impose in the United States. Most of the characters in Rainbow are American or British, however, the NATO countries of France, Germany, Canada, Italy and Spain, plus Israel have at least one representative each.
Clancy describes the structure of Rainbow as having one Director, who oversees the entire operation, and one Deputy Director, who is second in command. The name Rainbow Six depicts the corroboration between the counter-terrorist unit "Rainbow" and the British intelligence unit "MI-6". Rainbow is portrayed as the "blackest of black" operations, and it works off of its very own intelligence service which has intelligence contacts all over the world. In the book, when Rainbow is called upon for help from another country's government to deal with a terrorist situation, usually only one of the two teams will be sent, but in some situations both will be sent. Both teams have an officer as team leader and a senior NCO as second in command. Not including the team leader, each team is made up of eleven men. Rainbow also has a standard-issue weapons kit, consisting of a Beretta 8045 Cougar pistol and a suppressed H&K MP5/10 sub-machine gun (mislabeled as MP-10) for each soldier and a M60 for each team's support gunner. Each team also has two snipers, each with a rifle of own choosing.
In the games, Rainbow is portrayed differently. John Clark is still the leader for most of the series, but he is supported by a set of other key staff and advisors who vary from game to game. As of Rogue Spear, there are around 30 Rainbow operatives. This includes members from NATO countries and from non-NATO countries, along with six female operatives. For each mission, a maximum eight operatives can be deployed and can be split into a maximum of four teams. Weapons, uniforms and equipment are less standardized, and are instead chosen to suit the operative and the mission.
http://en.wikipedia.org/wiki/Rainbow_Six
Rainbow6.part01.rar
