Elite special forces are some of the best-trained and most formidable units a country can boast.
They go where other troops fear to tread, scoping out potential threats, taking out strategic targets, and conducting daring rescue missions.
These are the best of the best.
Though it's extremely difficult to rank these forces relative to one another, some units that rise above the rest with their track records and the fear they instill in their adversaries.
These troops have been through rigorous training exercises designed to weed out those who can't hit their exacting standards.
In a world in which the sheer size of a country's military is no longer the only guide to its effectiveness, these troops are the ones that states look to to get the job done.
Note that there are some graphic images below that some readers may find disturbing.
Tomas Hirst contributed to a previous version of this post.
8. The Special Services Group in Pakistan is better known in the country as the Black Storks because of the commandos' unique headgear. Training reportedly includes a 36-mile march in 12 hours and a 5-mile run in 50 minutes in full gear.
Source: "Pakistan Intelligence, Security Activities & Operations Handbook"
In October 2009, SSG commandos stormed an office building and rescued about 40 people taken hostage by suspected Taliban militants after an attack on the army's headquarters.
Source: The New York Times
7. Spain's Unidad de Operaciones Especiales — or the Naval Special Warfare Force, as it has been known since 2009 — has long been one of Europe's most-respected special forces. Established as the volunteer Amphibious Climbing Company unit in 1952, it has since become an elite fighting force.
See the rest of the story at Business Insider