Unfortunately, no one will take him seriously. : President Donald Trump got something right. His administration’s recent rule barring the use of federal funds to buy products made by the Chinese telecom firm Huawei is sound national security policy. So is his urging of allied governments to do the same. Even here, though, the Trump touch—the diplomatic equivalent of an inept gardener’s black thumb, turning even healthy plants to weed—has blighted the policy’s prospects. To be fair, it would be a hard row to hoe for any president.