What is the hardest military training in the UK?
British Special Forces selection is one of the hardest military tests. Listen to the stories of Special Forces veterans as they reveal some of the hard, sometimes gruesome, truths about the challenges of their training. Quiz. What percentage of Special Forces candidates pass selection? British Special Forces selection is widely considered to be one of the hardest in the world. The SAS and SBS hold two selection courses a year with 150-200 candidates in each.