When does The Diplomat return?

The Diplomat is an American political thriller television series created by Debora Cahn. The series stars Keri Russell as a veteran U.S. diplomat who is unexpectedly appointed as the ambassador to the United Kingdom amid an emerging international crisis. The show has been praised for its nuanced portrayal of foreign policy and the often invisible work of diplomacy. At the 77th Primetime Emmy Awards, the series was nominated for Outstanding Drama Series.
The series centers on Kate Wyler, the new U.S. ambassador to the United Kingdom. She helps to defuse an international crisis and forges strategic alliances. She also manages her deteriorating marriage to fellow career diplomat Hal Wyler.