Late yesterday, Sethuraman Panchanathan, whom President Trump hired to run the National Science Foundation five years ago, quit. He didn’t say why, but it was clear enough: Last weekend, Trump cut more than 400 active research awards from the N.S.F., and he is pressing Congress to halve the agency’s $9 billion budget.

The Trump administration has targeted the American scientific enterprise, an engine of research and innovation that has thrummed for decades. It has slashed or frozen budgets at the National Institutes of Health, the National Science Foundation, the Centers for Disease Control and Prevention and NASA. It has fired or defunded thousands of researchers.

The chaos is confusing: Isn’t science a force for good? Hasn’t it contained disease? Won’t it help us in the competition with China? Doesn’t it attract the kind of immigrants the president says he wants? In this edition of the newsletter, we break out our macroscope to make sense of the turmoil.

An investment

American research thrives under a patronage system that funnels congressionally approved dollars to universities, national labs and institutes. This knowledge factory employs tens of thousands of researchers, draws talent from around the world and generates scientific breakthroughs and Nobel Prizes.

It’s a slow-moving system, because science moves slowly. Discoveries are often indirect and iterative, involving collaboration among researchers who need years of subsidized education to become expert. Startups and corporations, which need quick returns on their investment, typically can’t wait as long or risk as much money.

Science is capital. By some measures, every dollar spent on research returns at least $5 to the economy.