An investigation earlier this year found that the death of a Navy SEAL during the fighting force’s famously difficult BUD/S training program was due to a lack of oversight and medical training. It remains to be seen what effect, if any, the investigation will have on one of the most legendarily elite and selective special forces units on Earth. 

World War II was the origin of many of the world’s most legendary military special operations teams. One of these is Great Britain’s Special Boat Service and Special Air Service, or SBS, which is comparable to the Navy Seals. (Also see: The US Military Special Forces With the Most Brutal Training.) The motto of the SAS is “Who dares wins.” The SAS gained worldwide fame in 1980 when in less than 20 minutes, they saved hostages being held by terrorists at the London Iranian Embassy, eliminating six terrorists and capturing one more in the process. Every hostage survived.

To determine the world’s 20 top elite special operation forces, 24/7 Wall St. reviewed lists of such units from RankRed, Spec Ops Magazine, Edudwar, Business Insider, and the veteran-led digital publisher The Mighty. Further information on the type of unit and their principal roles was taken from the unit’s website or from Wikipedia,.

Given the clandestine nature of their activities, and the fact that the tasks between the units can vary, these forces cannot be ranked. But we know from media accounts and some declassified materials which ones are the best of the best in the world. 

The original special forces date at least from the Roman Empire, which used small, speedy, camouflaged boats with specially trained soldiers for scouting and commando missions. 

Click here to see 20 of the world’s elite special forces