“Brothers! A hundred generations have defended this castle! It’s never fallen before; she will not fall tonight!” cried Alliser Thorne in a rousing speech. “And when the sun rises, I promise you, Castle Black will stand!”

For the three of you who don’t get the “Castle Black” reference, Thorne was a character in the HBO series and cultural phenomenon “Game of Thrones,” which recently ended but stands ready to be resurrected in spin-offs and prequels until the end of time. (What is dead may never die, indeed.)

Castle Black is not, however, strictly the fictional redoubt of the Night’s Watch — a military order that’s part-Catholic priesthood, part-French Foreign Legion and guards the northern border of GoT’s Seven Kingdoms. Last year, it was also a very real U.S. military base in Syria manned by Special Operations forces. Their remote citadel went by the name Mission Support Site Castle Black, according to documents obtained by The Intercept via the Freedom of Information Act.

There is no accurate count of the global number of U.S. military outposts and camps and forward operating sites and patrol bases and combat outposts and fire support bases and cooperative security locations and — well, you get the picture. There’s not even a comprehensive list of all the euphemisms that the U.S. military uses to avoid calling a base a “base.” But the estimate normally offered is around 800.

There isn’t a lot of publicly available information about Mission Support Sites either. The term pops up in a few Pentagon publications without much context. Some news outlets won’t mention the names of MSSes for “operational security reasons.” The New York Times actually published an article that could have mentioned MSS Castle Black but, instead of using its “Game of Thrones”-themed moniker, referred to it as a “base known as a mission support site.” To be fair, there is some disagreement as to the name of that Syrian outpost. In another document obtained by The Intercept, what appears to be the same base is called “MSS Nights Watch.”

The Pentagon’s 2019 edition of Joint Publication 4-04 “Contingency Basing” details a whole range of bases that are not called bases, including initial contingency locations, temporary contingency locations, semi-permanent contingency locations, contingency locations, cooperative security locations, enduring locations, forward operating sites, and main operating bases. The Department of Defense’s “Base Structure Report” includes the terms “DoD site” as well as “installation,” which it defines as a “military base, camp, post, station, yard, [or] center.” What neither mentions is the term “Mission Support Site” — nor why in seven hells the military needs yet more euphemisms to describe a base.

Thankfully, the U.S. military did, at least, fill in some blanks for The Intercept. It turns out that a Mission Support Site is the functional equivalent of an initial contingency location or a patrol base — marked by austere infrastructure and little outside support, according to the media operations staff of Combined Joint Task Force – Operation Inherent Resolve. CJTF-OIR, the U.S. military task force aimed at defeating the Islamic State in Iraq and Syria, also known by its Arabic acronym Daesh.

Citing “operational security reasons,” CJTF-OIR refused to provide the locations of MSSes or even a simple count of them. The task force’s media office would only say that Mission Support Sites were utilized by troops “working alongside partner forces in Iraq and Syria in support of the enduring defeat of Daesh.” Last year, President Donald Trump announced that ISIS had been defeated in Syria. Developments since then suggest this was a “Game-of-Thrones”-type fantasy. CJTF-OIR, for example, continues to fight the Islamic State in Syria and a recent report by the Inspectors General of the Department of Defense, State Department, and U.S. Agency for International Development noted that “thousands of ISIS fighters remain in Iraq and Syria and are carrying out attacks and working to rebuild their capabilities.”