Is it possible for the US to mobilize in a fight for survival?

I'm using allied posters from WW2 as a backdrop to my question.  Could the US (and it's allies) mobilize in a fight for national survival?

The posters are just a snippet of the effort carried out on the homefront to get people involved and supporting the fight.

We saw our entire industrial might, agriculture, and even human capital turned to the war effort.  From rationing gasoline, to planting victory gardens to encouraging workers not to take sick days, we saw the entire populace put on a war footing.

Could we do it today?

Would a modern war between peer nations start and finish so fast that it would be wasted effort?

If a war between peer nations occurred today, would it be of such intensity that if it were to last more than a year we would have to quit the field because of losses and not being able to replace them in a timely manner?

The question I guess I'm really asking is this.  The Commandant has joined me in stating that a big fight is coming.  Are we ready?  Or have we tailored our force to fight counter insurgencies to such a degree that anything bigger would break our armed forces beyond repair?