Does your neck hurt? That whiplash you just experienced is a result of Donald Trump blinking. It has been less than a day since his radical regime of “reciprocal” tariffs took effect. But America’s president has just put most of them on pause for 90 days. Dozens of countries had already come to negotiate, he said by way of explanation. The convulsing markets may also have affected his thinking. As our Lexington columnist writes, “Mr Trump’s own threshold for pain is not as high as he pretends.”