Unless a miraculous truce descends on a deeply polarized Congress before the end of this week, the US government will be forced to cram US$85 billion in across-the-board spending cuts into the seven months that remain of the fiscal year. Science agencies will not be spared. The$30.7-billion National Institutes of Health (NIH) will lose $1.6 billion; the National Science Foundation (NSF), more than$370 million; the Department of Energy’s Office of Science, $260 million; and NASA’s science budget, almost$270 million.

The cuts, known as ‘sequestration’, are already having an impact, as agencies pare back or cling to their grant dollars, anticipating the worst (see Nature 494, 158–159; 2013). In biomedical labs, postdocs are not being hired and equipment repairs are being put off. At the NSF, few, if any, new grants are being awarded.

Conservatives pooh-pooh the public alarm that the White House raised this week in a last-ditch effort to persuade Congress to avert the cuts. What programme of the oversized US government, they ask, cannot find 5% in excess fat to trim? Unfortunately, science agencies have very little. At the NIH, for instance, funding rates for grant applicants are already at historic lows: the agency spends roughly 85% of its budget in the extramural community, yet the chance of winning a competitive grant has fallen from about one in three 10 years ago to around one in six today. At the NSF, the odds are only slightly better, at just over one in five.

The risk is that these numbers will begin to look generous as the sequester takes effect. On 25 February, NIH director Francis Collins predicted that “hundreds and hundreds” of new grants, and grants competing for renewal, will not be awarded if the sequester takes effect. Furthermore, the agency has been holding back money from the instalments it owes on multi-year grants that were awarded in previous years; at any point in time, these constitute the bulk of its extramural spending and they will need to be cut to reach the $1.6-billion mark. Such instalments have been funded at 90% so far this year; under the sequester, awardees will never see the full 100%. The outlook is no merrier at other science agencies. NSF director Subra Suresh wrote to Senator Barbara Mikulski (Democrat, Maryland) this month that he will be obliged to reduce his portfolio by nearly 1,000 grants and to terminate$35 million in contracts for work already in progress on major facilities for environmental and oceanographic research. At the Department of Energy, cuts to the basic science mission will be “severe”, director Steven Chu wrote to Mikulski this month, affecting an estimated 25,000 researchers and operations-support staff at the ten national labs and compelling a reduction in both the size and the number of the department’s grants.

Researchers will leave the country, or they will leave science.

Opponents of the sequester worry not only about its effects, but also that the public is likely to notice them only gradually. For instance, the tens of thousands of government employees who are expected to be lost from agencies such as the Food and Drug Administration require 30 days’ notice, pushing noticeable effects into April. The loss of 2,000 disease trackers supported by the Centers for Disease Control and Prevention might not become apparent until the next time Salmonella poisons peanut butter. By the time the public outcry becomes sufficient to cause Congress to enact a remedy for the sequester, significant damage is likely to have been inflicted on science and on public health, not to mention the vast reaches encompassed by the rest of the government.

But for research, what is most deeply troubling about the looming cuts is not the absolute dollars lost or the immediate damage done, painful as that will be. It is what they both signify and portend, as the work of a profoundly divided government that shows no sign of being able to deliver, in anything like the foreseeable future, the stable, predictable funding that excellent science requires. Without that stability and predictability, not only will the United States’ lead in science and innovation continue to erode in the face of international competition, but, in an age of unparalleled scientific opportunity, the next generation of would-be researchers will begin, understandably, to vote with their feet. They will leave the country, or they will leave science. Either way, the United States and its people will lose.