U.S. Army Special Forces, also known as Green Berets, play a crucial role in helping allies to support U.S. security interests.

Unfortunately, as with the three Green Berets who were killed in Niger on Wednesday, their job is fraught with risk.

First off, it's important to note the difference between Green Berets and operators in the military's "special mission units" units, such as Delta Force and DEVGRU. Where Delta and DEVGRU are primarily tasked with direct action (think: capturing or killing terrorists/rescuing hostages) and covert action (think: infiltrating hostile territory and sabotaging or spying on enemies), the Green Berets are primarily tasked with training foreign forces in waging or countering insurgencies.

Operating in 12-person operational detachments (ODAs) known colloquially as "A-Teams," Green Berets frequently serve alongside less-capable or unconventional foreign forces. This week's incident in Niger evidences as much. The A-Team involved was likely from the 3rd Special Forces Group (which is oriented towards Africa), and was almost certainly assisting Niger's military in patrol and intelligence missions against terrorists. After all, the Mali-border area in which the Niger attack occurred is a hotbed of al Qaeda activity. In these mentoring-support missions, the Green Berets serve the long-term human development of American security partners.

Yet the Green Berets' true strength is their matching of an outsized punch to a tiny footprint. It's not just that these 12-person A-Teams are made up of highly-trained warriors, it's that they are experts in living deep inside hostile territory without logistical support. Put simply, the Pentagon knows that when it sends an A-Team to a high-threat area, its Green Berets will have the language, cultural, and combat skills to get the job done.

The cultural-understanding component of the Green Berets cannot be overemphasized. After all, if Americans on the ground can speak local languages and embrace local customs, they will be able to build the relationships to gather intelligence and conduct offensive operations. It's in this sense that Special Forces soldiers are at once academics, linguists, sociologists, and gunfighters.

Moreover, if the Green Berets are carrying enough money or operating with sufficient latitude, they can direct entire armies to great victories. This vast potential was best evidenced in the late 2001 U.S. ground offensive against the Taliban and al Qaeda. There, various ODA and CIA groups orientated the Northern Alliance into a massive offensive that drove America's enemies out of Kabul. A few hundred soldiers and few dozen bomber aircraft did what would have otherwise taken 100,000 soldiers.

So yes, while the Green Berets may lack the movie-star reputation of Delta Force and the SEALs, they are no less important to U.S. national security.