There may have been a time when American industry was something of stature, but those days are long past. It is impossible to underestimate America today.
The trough that you're witnessing in the military production capabilities in US, be it shipbuilding, aviation or ground force elements is born out of absence of a near peer adversary for almost 3 decades.
That may lead one into thinking that the US capability to out produce and outfight an adversary has reduced but it puts a veil on the underlying technical expertise and economic wiggleroom it has to ramp up its combat forces in time of crisis.
Time and again we have seen it change and augment its forces to meet combat demands in a rather rapid fashion, like WW2, cold war etc.
The force structure, and inherent support, production you see now is based on world policing/threat deterrence needs and not direct combat with peer adversary. This docile behaviour should not be mistaken as an inability and rather a conscious decision taken by the lawmakers.
Once a direct threat or casus belli is instilled into the US power structure, the initial stages of which is pretty much showing itself now, thats when the real picture will emerge.