Preventing a war?
Blue states, on the coast, could set up a blockade that interferes with trade to/from red states. We could worry less about that if we were more autarkic, but that would virtually invite foreign powers into those blue states that border the red ones. Would be a war then, but not a civil war.
The blue states aren't interested in keeping the red states in the union. The red states would be industrially self sufficient over time. They only hostility will be quelling any internal city boy strife.
Supply lines can quickly move to the gulf coast and Texas ports. The East/West coast will be hurting because the breadbasket is in the middle of the country not the coastal states.