OP approvingly posts a detailed article about waging war and killing domestic "enemies" who, it must be said, are guilty of merely being his political adversaries. One could argue with almost any other regular poster here that such approval would charitably refer to the alleged debate-worthy content of the article itself or of the inclinations of the writer himself. But with OP his approval is not reserved for the debatable qualities of the article nor the writer, but as his lengthy and focused history of past posts, missives and entries against his political adversaries here can attest his approval assuredly lies at least in part in the aims of the article itself. His politics and political heroes include spreading disturbing and deplorable
content like this. No one without a serious axe to grind would ever read and proffer this article as "a good look" into anything except as a good look into the pathological preoccupations of the writer in question. But OP did not intimate that, and frankly I seriously doubt he ever would.
The longer Oath of Allegiance includes the promise to "cause Her Majesty's peace to be kept and maintained". Approvingly spreading around the idea that one's domestic political adversaries should be killed is dishonouring that promise. Specific enough?
Tribalism and dehumanization are what make war prosecution possible. Active service members are the last people on Earth who should be cavalier with the tried-and-true processes of engendering tribalism and dehumanization. Whether or not OP agrees that is exactly what this article and many others just like it emanating from his political kin and allies are doing. Engender that tribalism and dehumanization within your domestic polity and civil war is a foregone conclusion.
Wondering "What Might Civil War Be Like" begins with determining who is fighting and on which side. If OP really cared about his oath to keep Her Majesty's peace maintained he should be much more careful about drawing, intentionally or otherwise, active service members into the fight.