 Operation Nimrod brought the SAS , a regiment that was largely unknown at the time owing to the covert nature of its operations , into the public eye . The regiment was not pleased with its new high profile , having enjoyed its previous obscurity . Nonetheless , the operation vindicated the SAS , which had been threatened with disbandment and whose use of resources had previously been considered a waste . The regiment was quickly overwhelmed by new applicants . Membership of 22 SAS is open only to individuals currently serving in the Armed Forces ( allowing applications from any individual in any service ) , but the unit also has two regiments from the volunteer Territorial Army ( TA ) — 21 SAS and 23 SAS . Both the TA regiments received hundreds more applications than in previous years , prompting de la Billière to remark that the applicants seemed " convinced that a balaclava helmet and a Heckler & Koch sub @-@ machine gun would be handed to them over the counter , so that they could go off and conduct embassy @-@ style sieges of their own " . All three units were forced to introduce additional fitness tests at the start of the application process . The SAS also experienced an increased demand for their expertise in training the forces of friendly countries and those whose collapse was considered not to be in Britain 's interest . 
