This is an extremified version of the general progress of technology in warfighting though: while we have the stories of automotive factories being converted to

This is an extremified version of the general progress of technology in warfighting though: while we have the stories of automotive factories being converted to produce tanks during World War 2, that was something that was only possible in the environment of the time. More then ever, you go to war with the military you have, the outcome is going to be decided very quickly because the rate of equipment attrition is enormous: military victory will be decided in weeks, not years (you can of course still lose the occupation, but that's a different matter).