Most of the US military is mostly made up of conservatives

That's a generous interpretation of the word most. Among active duty plus veterans the US military is 34% Republican. If you take out veterans it's only 26%.

https://news.gallup.com/poll/118684/military-veterans-ages-tend-republican.aspx

and red states are the only ones with some semblance of a manufacturing base

Straight up ridiculous nonsense.

https://www.industryselect.com/blog/top-10-us-states-for-manufacturing

California is not only top for manufacturing, but grows half the food in the country.

I dont think a hypothetical civil war will turn out as well as blue staters think.

It's not going to happen, not even in your wildest, most traitorous fever dreams.

I’m highly doubtful that a second Civil War would be like the first. I’m more of the opinion that we’d see something along the lines of the Troubles in Ireland.

Maintaining a fighting force requires a ton of money and the loss of international markets in the Civil War hurt the Confederacy greatly. Inflation in the Confederacy shot through the roof. Paired with the Union’s successful blockade, the Union securing most rivers, and the Union pretty much destroying every bit of infrastructure in the Confederate States, the Confederacy had massive economic woes that plagued morale.

I’m really doubtful that any State wanting to secede wants to lose access to the US dollar as it would wreck their economy. I just don’t see it being the way the Civil War was fought as it would almost guarantee a repeat.

Wars are fought along a lot more lines than just the ones where bullets matter.

Manufacturing is usually urban, and last I checked that's where most blue is. Farming and agriculture is red, sure.

Military is split, infantry probably skews red but the AF seems mixed and the Navy is pretty liberal in my experience.

Ok putting aside the obvious that 99% of US Military service members honor their oath to the Constitution and respect the chain of command serving the sitting President regardless of politics. Not least of which the DOD has been purging insurrectionist sympathisers the past few years.

So the brass tax of the US Military, our most valuable assets by a LOT are the US Navy. 2nd would be the USAF. Primary of which is arguably our Submarine force, followed by our sea warfare, then our air forces, and the rest of our nuclear arsenal.

Our largest sub base is in CT (blue).

The entirety of our carrier fleets are based in blue states - California, Hawaii, Virginia (blueish).

A significant portion of our nuclear stockpile is in Colorado (blue).

Anyway it all doesn't matter because any insignificant numbers who would defect would be nowhere near the command of these critical assets. The only real annoyance of Texas seceding would be having to relocate NASA HQ lmao.