This year has taken so many shocking turns that we have become immune to startling news. So when the Con­gressional Budget Office released its new long-term estimates of federal deficits and debt in September, almost no one noticed.

The figures were grim. The CBO expects the federal debt in 2050 to be twice as large as the country’s annual economic output — a level never ap­proached in our history. It estimates that spending that year will be about 31 percent of gross domestic product, up from about 20 percent today, while revenues will reach only 18 percent of GDP (up from 16 percent today). That means that annual deficits, which have averaged 3 percent of GDP over the past half century, will grow to more than 12 percent of GDP by 2050, and therefore that the scope of our debt will only grow further beyond the 30-year time frame that the CBO considered.

To the extent they drew any attention at all, these figures were implicitly integrated into our perceptions of the immense costs of the COVID-19 pandemic. At $3.1 trillion, this year’s federal deficit is about three times the size of last year’s — and is larger, relative to the economy, than any we have seen since 1945. As a result, the federal debt is now larger than the annual output of the economy (at 102 percent of GDP), again for the first time since World War II.

But temporary emergency spending is one major reason why we have a national government. Next year’s deficit will likely be far smaller, and the long-term trajectory of federal finances is not a function of pandemic response. It is, rather, a function of a multigenerational failure of responsibility. And in no small measure, this has been a failure of conservatives.

The Republican Party has styled itself the party of fiscal restraint for the better part of a century, and there has been no shortage (at least until lately) of Republican elected officials raising alarms about the debt. But there hasn’t been much action, or much willingness to expend political capital or make some painful deals to achieve a meaningful change in the trajectory of the government’s finances. The story of why that has happened has a lot to teach us about the difference between political rhetoric and policy action.

At the heart of that story is the same confusion evident in the response to this year’s numbers: a confounding of discretionary and entitlement spending. We conservatives have approached the entitlement question through the lens of spending restraint, and so have repeatedly commingled it with our distaste for waste, if not for public spending in general. The energy and political capital that might have been spent on getting the debt under better control has therefore mostly been spent on marginal reductions of discretion­ary spending.

So, for instance, while there have been some meaningful Republican efforts to put Medicare and Social Security reforms on the table over the past three decades (efforts led by Newt Gingrich, George W. Bush, and Paul Ryan above all), these have gone nowhere, and the only fiscal reform Republicans can claim in this period has been the discretionary caps ad­vanced by the Tea Party in the Obama era. Those caps, which are now expiring, did restrain spending a bit, but they have not changed the upward course of the government’s debt, because discretionary spending is not where the problem lies.

As a share of the economy, federal discretionary spending has been trending downward for decades: It was far lower in 2019 than it was in 1970 or 1980. And the CBO projects that it will be lower still three decades from now. But entitlement spending has been exploding, and will only grow faster in the coming years.

Confusing discretionary with entitlement spending has often left conservatives arguing for austerity (which is neither popular nor generally wise) while leaving the government’s actual fiscal problems essentially untouched. We have been left urging less of the same, rather than thinking about changing how government works, to also im­prove the nation’s fiscal prospects.

Ironically, the willful blindness of the Trump era might offer us an opportunity for such rethinking. Entitlement reform has been a rare ground of bipartisan agreement in the past four years: Both parties have agreed to forget about it. That means the underlying fiscal problems have grown worse during this period. But it also gives us a chance to approach the question of the national government’s finances afresh. Doing so might point us toward three general premises.

First, the costs of fiscal irresponsibility have more to do with constraints on future growth and spending than with the risk of catastrophic crisis. Growing debt makes claims on the government’s finances in the years to come, and so burdens future taxpayers while limiting the options of future legislators. The problem, in other words, is that debt and interest payments will dramatically constrain the government’s capacity for discretionary spending — on defense, on welfare, on research, on emergency response — and will also constrain our economy’s capacity for prosperity.

There is always some chance that our borrowing could destabilize the government’s fiscal foundations, too, undermining its ability to finance further debt and so setting up a dangerous crisis. But the past ten years have suggested that the hunger for our debt in global markets runs deep, and that our capacity to borrow may not be much constrained by the risk of scaring off investors. That lesson should not be overlearned: There is presumably a limit to our borrowing capacity. But the lesson should not be ignored, either. We do have room to borrow, if that is our choice. This is good news, but it also means that if we are to avoid needlessly impoverishing our future selves, we will need to summon the will for restraint.

Such restraint is needed because most of our borrowing is being used not to enable investments from which those future selves (or future generations) might benefit but rather to provide for current consumption by recipients of public benefits — especially by the elderly, who are on the whole among the least needy people in our society. This is the second premise that should guide our thinking: The debt problem is an entitlement problem. Conservatives will need to separate whatever general distaste we might have for government spending and waste from our worries about public finances.

But the third premise of our fiscal politics is that the public desires the benefits provided by our entitlement programs and that they will not be significantly curtailed. Conservatives can chafe at this fact all we want, but Republican politicians will not be much more willing than Democrats to cut benefits for current recipients of Social Security, Medicare, or (at the federal level, at least) Medicaid. Fiscal reform will need to involve changes to these programs, but those changes will need to be forward-looking, allowing these programs to continue meeting their important aims — if by different means.

These three premises gesture toward a different approach to fiscal reform. They require fiscal conservatives to focus on what matters most. This means not looking to the discretionary budget for significant savings, which tends only to undermine the case for entitlement reform without helping to alter the trajectory of the country’s debt. Repub­licans should be willing to make bargains that involve leaving discretionary spending untouched, or even on a path of modest growth, if that allows for some reforms of entitlements.

They should also be willing to contemplate tax increases and reforms that move the burden of federal revenue upward on the income scale, provided such changes do not unduly undermine growth. This is a matter of prudential balance, not absolute principle. The assumptions that cutting waste will save the budget and that all tax increases are equally harmful have functioned as rules of thumb for conservatives for 40 years. Those assumptions need to be retired in the name of dealing with reality responsibly. They are not true, and therefore not helpful.

Finally, fiscal reformers should empha­size large changes that will make a significant difference over time. There are many ways to trim some costs in Medicare and Medicaid, and even in Social Security, but they tend not to add up to much. Focusing on them leaves reformers expending political capital without making a difference. It would make more sense to think about gradually altering the basic structure of Medicare and Social Security for future beneficiaries in ways better suited to what are now those programs’ core aims.

My American Enterprise Institute colleagues James Capretta and Andrew Biggs have proposed such reforms of Medicare and Social Security, respectively. Each would take effect only gradually, without reducing current retirees’ benefits. And in each case, the program would ultimately provide a set base benefit to all retirees and additional help for those with lower incomes, and do so in a way that better serves the program’s aim of keeping retirees out of poverty, offers more help to those in greater need, and gradually but significantly improves the government’s fiscal prospects.

The case for entitlement reform is not a case against government action, or even, exactly, against government spending. It is a case for sustainability, for providing the rising generation with its own entitlement: an entitlement to the same range of options, for both personal prosperity and common action that its elders have enjoyed. It is in other words a case against burning the future as fuel for present consumption — and so a classically conservative case that our society needs to hear.