Besides the prospect of a government shutdown or a default on the national debt, the most destructive aspect of the federal budget impasse is the sequester’s damage to basic scientific research, especially biomedical research.

Almost everyone agrees that across-the-board cuts in discretionary spending — which make up just a third of all federal outlays — are a poor substitute for debt reduction that includes entitlement reform.

But the continuing failure to address the debt comprehensively means that the sequester may go on indefinitely.

Many federal agencies undoubtedly can afford a 5 percent haircut without damaging the national interest. But chopping research — already underfunded — is worse than eating the nation’s seed corn. It’s like letting it wither in the fields or feeding it to the pigs.

Even though federally funded research laid the basis for the success of major employers such as Google, Sun Microsystems, Genentech and Cisco, its funding as a percentage of gross domestic product has fallen by more than 30 percent since the mid-1980s.

According to the American Association for the Advancement of Science, the budget sequester is cutting total federal research-and-development funding to below 0.8 percent of GDP, its lowest level in 40 years.

Fifteen years ago, Congress and the Clinton administration temporarily reversed the trend, doubling the budget of the National Institutes of Health in four years. George W. Bush finished the project. But the budget has been flat since 2003.

The combination of inflation plus a $1.6 billion reduction mandated this year by the sequester has cut the NIH’s research power by 20 percent. “We’re being undoubled,” NIH Director Francis Collins told me.

After the doubling, nearly a third of the qualified research ideas submitted to NIH got funded. Now, the number is down to 14 percent — a reduction of nearly 700 this year alone.

The cuts are crippling the biotechnology industry, sacrificing what has been a major U.S. job creator and world leader. They are forcing young scientists we’ve spent a fortune educating to look for other work or go overseas.

Worst of all, they’re going to kill people.

Among its research projects, the NIH has been funding work on a universal flu vaccine that could prevent a pandemic killing millions.

The sequester demands a 5 percent cut across the board at every one of the NIH’s 27 institutes and research centers, including the one concentrating on infectious diseases. So, there’s a slowdown in work on the vaccine.

In a normal year, about 40,000 Americans die from influenza and about 500,000 die worldwide. But the 1918 Spanish flu epidemic may have killed 100 million. In another such outbreak, the toll would be even higher.

Or, take cancer. Thanks in part to NIH-funded research, the U.S. cancer death rate has fallen 15 percent in the past decade and a half, but 580,000 people still die of it annually in this country.

Instead of carpet-bombing all cancers with chemotherapy, surgery and radiation, researchers are using genomics to develop personalized treatments for various kinds of cancer.

Now that work has slowed, too, because of cuts at the National Cancer Institute and the National Human Genome Research Institute.

Collins told me he has met with more than 100 members of Congress to plead for an undoing of the sequester. The Senate Democratic budget does it. Collins said that most House Republicans tell him, “‘You’re right, but there’s not much I can do.’” They certainly ought to try.

As Collins says, this could be “the century of biology,” leading to the conquest of major diseases and the development of new energy and food sources. But it won’t be America’s century if the government keeps slashing research.