Anyone seeking to gauge the imminent outcome of the international talks over Iran’s nuclear program being held in Vienna should take a look at reports from late January that three top U.S. diplomats had quit—largely in protest over the direction set by U.S. Special Envoy for Iran Robert Malley, who serves as the U.S. government’s chief negotiator. Having served for two years in former Secretary of State Mike Pompeo’s Iran Action Group, I knew that this development was tantamount to a public cry for an intervention. Such resignations—not of conservative dissenters, but of career staff and President Joe Biden’s own...