Since you state in your question as a premise that in this hypothetical scenario everyone agreed to stop being a capitalistic republic (i.e. No capitalism and no representative democracy) then the most likely result of that being imposed - namely insurgency against the tyrannical new order, is not likely. Your question includes the following: "What economic and political systems would better meet the needs of today?" which implies that there are such better economic and political systems.
That is a supposition that is not supported by historic fact. In my opinion it would take major upheaval to destroy the effectiveness of our current economic and political system. While such might happen, there are not high probability processes that would lead to it.
To answer the question then requires coming up with might be plausible causes for the people of the US to make such a choice. Here are some more or less plausible scenarios.1. The economy collapses completely (think pre-WW-II Germany).
2. Enemy attack wipes out much of our leadership and much of our economic power (surprise attack with WMD, most likely biological, though possibly nuclear).3. A plague decimates our leadership and production capacity.4.
Global climate change causes the US to be completely over-run by refugees from Central and South America to the point that these refugees are a majority.In each scenario, the outcome is likely to be different, at least to some extent.1. In scenario 1, a charismatic populist leader will probably arise and through democratic means change the system to a non-democratic one (similar to Adolf This will cause a greater separation between haves and have-nots, but along lines of who supports the new tyrant most vs. who is more reluctant. With the economy in shambles, the new leader will probably be forced to start a war abroad to bring in more resources and divert domestic discontent.
One would hope that there would be sufficient power in the rest of the world to stop such a person. 2. In scenario 2 or 3, the country may end up split into multiple smaller nations, each struggling to allow its people to survive leading to a multi-sided civil war between what were previously states in the Union.3.In scenario 4 the country may turn into an apartheid-style country, where the refugees are not given political voice, and are used for cheap labor (near-slavery of the refugees), and ultimately either to another civil war or to a revolution.
In any of these, one would hope that reason would ultimately prevail, and a new democracy, or at least a constitutional monarchy (England-style) will be born from the ashes of the old.
If Americans decide one day to abandon capitalist democracy, the most likely successor would be an Utopian Beerocracy. Ever since its founding, America has seen repeated attempts at creating Utopian communities and communes. So far many of the attempts were quite successful for a few years or decades, but always at about the level of a small, rural town.
This is really the only alternative to capitalism and representative democracy that has been tried by Americans. It's always been popular but it just hasn't scaled well. One example are the Amana colonies.
They are remembered for enjoying singing the Schnitzelbank song. Singing joyful music is good for bringing a community together, as is beer. A utopian community that gathered at its local beer garden for some brew and singing might be more persistant than others.
The Deutsches Haus in New Orleans has been going 83 years as a less ambitious organization with those traits. Perhaps with the resurgence of microbreweries and brewpubs, and the superior communications of the internet, America could transform itself into a network of small, beergarden and Gemuchlichkeit based communities. As Teddy Roosevelt said in a 1906 speech, "No greater contribution to American social life could possibly be made than by instilling into it the capacity for Gemuthlichkeit."
Someday perhaps Americans will wake up and just create a new society based upon Utopian Beerocracy.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.