What started out as a counterintelligence investigation to guard the United States against a hostile foreign power has morphed into a political scandal about what Mr. Trump did, what he said and what he meant by it. 

WASHINGTON — President Obama and Secretary of State John Kerry have a simple explanation for their surprising success in getting Iran to dismantle much of its nuclear infrastructure, ship out 98 percent of its nuclear fuel and release five American prisoners: Patient diplomacy, backed by escalating economic sanctions, accomplished more than military action ever could have.

David Sanger, senior fellow at the Belfer Center and adjunct lecturer in public policy at Harvard Kennedy School, was interviewed on NPR’s “On Point” about his new book on President Obama’s foreign policy efforts, including a cybercampaign against Iran’s nuclear program. Sanger’s book, Confront and Conceal: Obama’s Secret Wars and Surprising Use of American Power, was published this week.