Gene Steuerle, a fellow at the Urban Institute who specializes in national debt and tax policy matters, was among 40 notable individuals asked to respond to the question “Has the world been fitted with a debt straightjacket?” by the publishers of The International Economy last spring. His response provided the following gem that summarizes the origins and problems with the United States’ growing national debt in just three short paragraphs:

For most of history, nations with even modest economic growth wore no long-term fiscal straightjacket. Even with the debt levels left at the end of World War II, economic growth led to rising revenues, while most spending grew only through newly legislated programs or features added to programs. Typically existing programs were expected to decline in cost, e.g., as a defense need was met or construction was completed. Until recent decades budget offices did no long-term projection, but if they had, they would have revealed massive future surpluses over time even when a current year revealed an excessive deficit. Year-after-year profligacy was still a danger, but it wasn’t built into what in the U.S. is referred to as “current law.”

Today, rising spending expectations are built into the law through features such as retirement benefits that rise with wages, expectations that health care spending will automatically pay for new innovations, and failure to adjust for declining birth rates and the corresponding hit on spending, employment and revenues. At the same time, officials fail to raise the revenues required to meet, much less fund, those laws or voter expectations.

A rising debt level relative to GDP is merely one symptom. Reduced ability to respond to the next recession or emergency is another, while the increasing share of government spending on consumption and interest crimps programs oriented toward work, investment, saving, human capital formation, and mobility.

The following chart, which is based on data from the Congressional Budget Office’s 2017 Long Term Budget Outlook, illustrates those three short paragraphs.

Summarized into one sentence: U.S. politicians have promised far too much spending in the future than can ever be sustained without causing great harm.