The attacks have been fast and furious. In a matter of months the Trump administration has cancelled thousands of research grants and withheld billions of dollars from scientists. Projects at Harvard and Columbia, among the world’s best universities, have been abruptly cut off. A proposed budget measure would slash as much as 50% from America’s main research-funding bodies. Because America’s technological and scientific prowess is world-beating, the country has long been a magnet for talent. Now some of the world’s brightest minds are anxiously looking for the exit. Why is the administration undermining its own scientific establishment? On May 19th...