From a military perspective, wouldn't there be a war even if Texas were to legally secede? The number of military and federal bases there makes for a problem; they won't just give those up, besides considering the loss of a big state. The pressure from it could be an excuse to ratchet up excuses for a fight. I'm not sure what excuse they'd make for violating the secession rules to try to fuck over Texas, but pretty sure they'll try if secession happens. Probably say the secession was triggered by MAGA domestic terrorists and doesn't count.

Even though Texas is the only one with the secession path legally, a secession with red states together actually seems more plausible.