In 2017, months after leaving government, I learned that some Americans at our embassy were harmed in mysterious attacks—from a sonic weapon or some kind of toxin. I knew that the Cuban government had never done something that brazen, even at the height of conflict with the United States. Whoever harmed those Americans clearly wanted to sabotage the opening between our countries, and I wondered whether the Russians who took such an apparent interest in my efforts had played a role.
