Structurally the USA and USSR are way more alike than anybody wants to admit. Both kind of got taken over by their respective defense industries after the Second World War. Leads to a bad cycle of internal disinvestment that hollows out a country in a kind of national metabolic crisis.
I think you're exactly right - splits within the military are what may ultimately crack the country. A lot of Americans are already more loyal to their states or regions than the nation as a whole.