Major divisions remain between Iran and six world powers as U.S. Secretary of State John Kerry and Iranian Foreign Minister Javad Zarif prepare to meet in Geneva on Saturday, a month away from a deadline for a final nuclear deal. People involved in the talks warn that political pressures could still delay—or even derail—a deal as the two sides flesh out the broad agreement they reached on key issues in Lausanne on April 2. While much of the focus in the spring focused on the Obama administration’s struggles to prevent congressional opponents from blocking a deal, diplomats say it is growing political pressure in Iran that now poses the greatest risks. Among the toughest issues to resolve is one that has complicated diplomacy for years: access to Iranian scientists who worked on nuclear policy and to sites both to ensure Tehran doesn’t cheat on a deal and to answer […]