The United States and Russia exchanged prisoners in Abu Dhabi on Thursday, as Washington and Moscow edge toward a diplomatic rapprochement. Russia released Ksenia Karelina, a U.S.-Russian dual national, who was found guilty in Russia for donating a small sum to a U.S.-based Ukrainian charity and was sentenced to 12 years in prison. Karelina, a former ballet dancer, became a U.S. citizen in 2021 after marrying an American and moving to Los Angeles. In exchange, the U.S. freed Artur Petrov, a German-Russian dual citizen who was arrested in 2023 in Cyprus at the request of U.S. authorities for allegedly exporting...