After three months of war with Iran the U.S. government’s borrowing costs are at their highest since 2007, with American taxpayers potentially having to cover billions of dollars in interest. All this is unfolding since the national debt surpassed the size of the U.S. economy in late March. What does this spell for the country’s financial future? Maya MacGuineas is the President of the nonprofit Committee for a Responsible Federal Budget. She speaks with Walter Isaacson about what policymakers might do to reel in this crisis.