This is a link to the first part of a vid on Youtube about the SAS, you might not be that interested in British forces, but its talks about the development of Special forces and counter terrorism. There is a lot of stuff about the IRA and The Iranian embassy seige on it.
I believe that the terrorists behind the Seige were funded and support by Saddam Hussein.
The other parts are linked on the same page. Interesting picture of Thatcher and the SAS which was supposed to be destroyed.