I'm sure there's a dozen libertarians on this forum alone, I remember discussing it with them, who'd claim that what has "won" out in the world isnt capitalism, at least not their dreamt of capitalism, the problem arises when their proposals only serve to strengthen the supposedly un-capitalist status quo instead of conjuring up their paradise.
And do you think the US will adjust by introducing a mixed economy with government ownership of utilities, health services, social services and a progressive taxation?I think our military is horribly inefficient when it comes to spending and that we need a meaningful reduction in military spending, while at the same time not compromising our global force projection (which is entirely possible).
The only reason we could pay for everything as long as we did is that we were growing at an unusually high rate after WWII, eventually we got used to that level of growth, and when it started to slow we artificially stimulated it in the 80's and again in the 00's.
We can no longer afford to promise the moon and the stars to every constituency under the sun.
We have to adjust to the new normal just like Britain had to adjust to a world where they were no longer uniquely dominant.
If you want to draw that analogy the UK became positively "socialist" following its paradigm shift from empire, in fact most of the UK socialists didnt think that their reforms were singularly socialist at all but would prevent spending upon the military and militarism of the kind which had historically determined all national economic and social policy.
Accepting your analysis for just a moment, which I do think is flawed BTW, why did the US decline after WW2? How could it possibly have been artificially stimulated in the ninties and noughts? I presume you're talking about the Democrat periods of office and I also presume that you believe they make the promises to constituencies and the republicans dont.
The reality is that both the UK and US have been dominated by domestic "old money", its unproductive money, globalisation has been debated back and forth but the political consensus is that it has empowered all money, including "old money", unproductive money, to resist taxation so the state cant even circulate money in the economy productively. The crisis created by shady "new money", the golden geckos, attempts to create and keep shares of wealth and places at the table now threatens "old money" but the narrative that everyone should take a hit and it was all unaffordable anyway is holding for the time being.
Whether people believe it or not and whether "old money" can be protected for a little longer or not the reality is that unproductive money and legacies are not going to create any shared prosperity, I'm not sure that they can even guarantee their own prosperity relative to everyone else indefinitely, those fortunes will eventually dwindle, especially if expectations just carry on as they always have and even escalate with each passing generation.