(a)In terms of world empires, the US empire wasn't/isn't much more than a pebble compared the British empire (and don't start going on about the 'war' of independence - that just made US economically unprofitable for exploitation, it was a loss in the same way that the US 'lost' the Vietnam war - the Brits could have steamrolled the US just like the US could have nuked Vietnam (or just razed it to the ground), but blowback and vulnerabilities from other genuine world competitors at that time made it unviable. The US empire isn't even really as powerful as the Spanish empire at its absolute height. The world survived those, and with China and the former 3rd world lifting their production the US collapse will be barely a speedbump.
(b) You want to know just how much the US economic collapse means to the rest of us. In Australia we've had a boom throughout your entire recession. Despite having state-run universal healthcare and all those goodies that you call either 'socialist' or unaffordable - even having those didn't stop us from being utterly unaffected by your economic self-implosion. Oh, and our debt is around 3% of GDP (and we freak about that - your debt, from memory is around 60% or more of your GDP...), if you want an idea of how little a relationship there is between large gov't (or medium gov't in our case) and debt.
(c) The US isn't going backwards so much as it is missing out on an increasing proportion of what the developed world takes for granted. Universal healthcare is the popular example at the moment, but in most first-world countries there's programs - funded - to pay for retraining and even relocation. Sure, students might have rental difficulties if they're doing a course with long hours that prevents them from working part-time, as the gov't allowance is a little bit low, but to actually have to PAY for classes would be unthinkable. It would just be crazy - the economy benefits from having people in work, so why would you place economic barriers in the way of economic fluidity? And these aren't countries that are socialist - it's just standard first-world practice. Your popular perspective of what is economically 'socialist' is skewed in a way unique to the US alone.
For most of the last 50 years, the US had among the highest production/person but always had a problem with distribution in that the average person had such a low share that the standard of living was worse than for poorer countries. But now countries like Australia are actually richer than you guys in terms of production per person (yes, 'per person', OBVIOUSLY
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), AND your distribution problem has become worse than ever.
It seems that you've got yourselves to the point that you've reduced your taxes below the level needed to maintain a functioning state, and that the US is no longer able to paper over the gaps in its infrastructure - and by that, I mean economic infrastructure - readily available and effective higher education and vocational training, if there's jobs available in engineering and there's an unemployed truck driver that has the brains and the ability to be a good engineer, then the economy needs to provide a path to get that guy trained and into the engineering job where he can actually contribute. If your society is so stratified that solid chunks of the population just can't access the means of economic progression, or can't change sectors when technology makes old ones obsolete, then sooner or later things are going to implode.
Over here, and everywhere in the world that I've travelled (which is pretty much everywhere except south america), it's taken for granted that this is what is happening to the US. In the main conservative newspaper over here, The Australian, the economists/forecasters taking the most OPTIMISTIC view (for the US that is) are saying 'don't worry, the US will remain a dominant power for WAY longer than people think - they won't lose power until around 2050-2060'. 2050-2060 is the outside estimate for the longest that we expect you to remain dominant. That's the optimistic best case scenario for which other countries are preparing. And it seems that you guys are hell-bent on speeding that up cutting your infrastructure even further and refusing to even contemplate addressing your debt by raising more revenue (taking a realist position that you've probably snookered yourself militarily into a position where you can't actually get a significant withdrawal for some time now).
You wouldn't even necessarily have to raise the taxes for the average person that much. The GST - a consumption tax on all goods and services - was considered ultra-right-wing when it was introduced by our conservatives over here, but for you guys it would actually be a more progressive system than what you have - you could increase your revenue considerably without raising taxes overall for the average person. And at least it provides a secure tax base that can't be avoided through creative accounting. Heck, I'm not saying that that's your magic answer, or even that it would necessarily be a good idea, but you've got no chance, zero chance at all, unless you find a way to fund infrastructure and economic/social fluidity.