For a long time, everyone knew that Greece was never going to pay all its debts; they were just too large. Lo and behold, Europe’s leaders put their heads together and announced a plan to have banks accept 50 cents on the euro for them. There’s a lesson for us Americans in all this, but it’s not about profligacy.

We all know that lesson full well by now. No, the lesson for us is that we’re not going to pay all our debts either. This will seem shameful to some of us and justifiable to others, given the policies and practices that led to so much debt in the first place, and the big-money bailouts that followed.

Yet there’s nothing evil or unusual about restructuring a debt; it happens in business all the time. The risk of default is built into the cost of a loan. And creditors, in their guise as bondholders, have already benefitted hugely from government guarantees and low interest rates.

But I’m not here to argue morality. My point is simply that some significant level of nonpayment is inevitable. And as in Europe, here too it would be better if we all acknowledged this and found an orderly way to wind down the unpayably large liability that overshadows our economy. For a disorderly default, even one that happens in slow motion, would be a disaster. As the rest of Europe has learned from Greece, pretending we can just go on as we are isn’t an option.

For example: lately it’s been noted with alarm that young Americans have amassed nearly $1 trillion in student debt, a fivefold increase over just 11 years. Well, a big chunk of that debt will never be repaid. And I say this knowing full well that most of this debt can’t be discharged in bankruptcy.

Another example: Homeowners with mortgages have negative equity of around $750 billion. A lot of that won’t be repaid, either. Ditto the $2.4 trillion in outstanding consumer credit (which includes college loans, but not mortgages).

Of course, a lot of this debt will be repaid, just like a lot of Greece’s. But there is no way we’ll pay all of it — not in a functioning democracy that, sooner or later, must take notice of its citizens. Creditors are powerful, and nobody wants the financial system to collapse. But with this much owed, debtors are powerful too. And ultimately, politicians know where their bread is buttered — which is why laws will be changed, if necessary, to let a lot of people off the hook.

The political system is already starting to acknowledge this. President Barack Obama has accelerated a plan to ease student debt for some low-income borrowers. He’s also announced another modest home-refinance initiative, which by lowering some mortgage rates has the effect of reducing the debt burden (at the expense of creditors).

There’s more to come. Calls for massive refinancing relief and principal reductions for homeowners are rising from all quarters, including no less than Glenn Hubbard, who was chairman of the Council of Economic Advisers under President George W. Bush. His plan is quite sweeping.

The government can’t just assume all this debt; that would only mean burdening taxpayers with it, and we’re the ones it came from to begin with. Besides, your dotty uncle in Washington is already on the hook for $6 trillion in mortgages and mortgage bonds, much of it from the collapse of Fannie Mae and Freddie Mac.

Then again, I doubt that even our national debt will be repaid in full. We won’t default, surely. But we may inflate, paying off all those Treasury bonds in devalued greenbacks. A return of inflation would hardly be welcome, since many would suffer as a result. But let’s face it: with all this debt, somebody’s got to take a hit. The likeliest victim is all of us.

Daniel Akst is a columnist for Newsday on Long Island, N.Y.