You have done your research, needless to say! Your question has been my bitch for over 10 years now. Not that it directly affects me as I'm not an American nor do I live in the USA... But the bottom line is, the US can no longer ignore the interest on their national debt, let alone the principal that was borrowed in the first place.
The latest numbers I have found, is that around 60% of every tax dollar brought in each year by the American Fed, goes directly to pay interest-only on America's national debt. But of course, even 60% no longer covers the tab! As you know, that is precisely 'why' the debt ceiling has had to be raised so many times in the last number of years, just to allow more money to be borrowed by the Fed. Truth is, that new borrowed money is what is being used to pay the monthly interest payment on old debt interest that is still outstanding. Borrow money to pay interest... What a novel idea! Americans are smarter than we give them credit for after all!
But apart from all that boring, depressing shit, it is not what Americans-at-large are going to do about their mounting, un-payable debt, but rather, what other countries around the world are going to do about accommodating the failing American empire in the near-years to come.
For example, I will speak of what Canada has been organizing for Canada's own financial survival when the US economy collapses. Ever since the American-led banking meltdown of 2008 of which the USA has still not recovered from, Canada then began distancing itself financially from the US in terms of doing trade with America.
Prior to 2008, Canada sold 80% of its export goods to the US. Today, Canada sells closer to 45% of it's exports to the US. The balance of Canada's exports are now going to Pacific Rim countries. The reason for this is that Canada is pre-positioning itself for the eventual Great Reckoning that will take place in the American economy, which will occur when the US uses up the balance of it's known oil reserves. Oil researchers say that this will occur in 10 years from now.
Canada tried to sell the Americans crude oil which would be piped right to their refineries in Texas, but Obama cancelled the construction of the Keystone pipeline which ran south of the Border. Canada had already completed their end of the pipeline when Obama cancelled the US interest in the deal. What then took place, was the installation of an elbow in the pipe on the Canadian side... basically a metaphorical 90 degree bend in the southbound pipeline right at the Canada/US Border, which now diverts that same crude oil due-West to the Canadian west coast.
From there, Canadian crude has been loaded on super-tankers bound for places like China ever since the Americans walked away from the deal. They walked away because they had no money to pay for their half of the pipeline which ran south of the Canada/US Border to Texas. The funny thing is, that pipeline snakes itself through the Canadian Rocky Mountains and that crude oil is pumped through almost a thousand miles of 12 inch pipeline to the loading platforms in Vancouver Harbor. And the job was completed and paid in full rather quickly!
The same thing goes for lumber exported from Canada. Now, Asian markets purchase every stick of raw timber that Canada can cut for them which was otherwise destined to America. The reason for this new export destination is for pre-positioning Canada's softwood lumber export market long before the shit hits the fan south of the Border.
Any country that is heavily attached at the hip to the USA like Canada use to be, will be brought down in flames by default when America flips over onto it's back and enters into a spiral dive... kamikaze-style. That is why Canada is now detaching itself financially from America earlier than most countries whom are still playing roulette in the American game, because the ultra-conservative Canadian Government can see the writing on the wall.
Canada also has a bird's eye view over the back fence of the absolute truth behind the grand illusion of the so-called, 'American Dream'. And when you add the financial incompetence of Donald Trump to the equation, keep in mind that Trump's own Real Estate empire has been slowly collapsing ever since the introduction of Amazon.com to the retail sales market.
Trump buys retail stores then rents them out to retailers at exorbitant rental rates. But few people shop in retail stores anymore since Amazon showed up for online purchases and delivery. Trump's retail vacancy rates in Manhattan NY are bordering on 80%. This means the leases are cancelled as the retailers are going broke. Only 20% of Trump's retail space is currently occupied in New York City. The Trump Hotel in Toronto for example, has been 100% vacant since the date of it's completion, of which Trump Junior was the Project Manager during it's construction. The Trump Brand Name is history. Trump however, is still trying to run America like he runs his failing corporate business empire. Trump has exponentially accelerated America's own race ..with itself ..to the bottom.