You prove my point. The outcome of this battle did not turn on a slugfest between tanks, with the side who could produce more winning.
How would we defend against an armored column invading our territory. M1-A1's or A-10's? Would the outcome of that battle in any way hinge upon manufacturing capacity?
Winning involves taking and holding ground. The tank is one of the best ways to do that. The A-10 is excellent at preventing other tanks from taking ground. The A-10 is a defensive weapon.
The seeds of destruction of the auto industry are solely the property of the Bolshecrat party and their allies the UAW. The Bolshies have had a hate affair with hydrocarbon base fuels for decades and have countered market forces to advance their agenda. Witness, the requirement from Nancy Pelosi, that before Detroit get any money they have to come with a marketing plan to produce green cars. You will see laws come out of congress to punish foreign owned auto production, like card check. And, laws that offset low tax states competitiveness. I expect we will be see the rise of the UBW (United Bicycle Workers) at $75 an hour to build the ultimate green means of transportation before the end of the next congress.
If that theoretical battle you submit lasts more than a week or two, you bet your bippy that manufacturing capability starts to matter.