What we are will probably face will not be a 19th century type war, with opposing armies, uniforms, codes of conduct, etc.
The Left cannot win that type of war, especially if our military is on the side of the Constitution.
That is why they have already waged a very different war. Their weapons are domination of the culture, domination of the media and Hollywood, propaganda, control of social media, vote fraud, judicial activism, and the tools of the Deep State.
But, let's say that there are mass arrests of the guilty (just for the sake of argument). Would the Cold Civil War go hot? It already has in pockets. Antifa, the false flag events (school or mass shootings, train derailments, etc.)
If the Left and the Deep State felt cornered and desperate, I guarantee you they will turn violent. They will use regional violence in places where they have an advantage. They will utilize corrupt police forces, or perhaps even corrupt National Guard that answer to Governors under Title 35.
Our Federal military (who operate under Title 10), may be called upon in many ways, to include arrests, and to quell riots or insurrections.