In its fourth season, The Diplomat is as twisty as ever — maybe even more so — including a finale that portends a massive shake-up for a presumed Season Five. The cast, particularly Keri Russell, Rufus Sewell, and Allison Janney, remains award-worthy. Meanwhile, the political drama, which deftly mirrors real-world American politics, keeps the series one of the most bingeable on Netflix. However, because it has been four seasons, showrunner Debora Cahn clearly wants to delve deeper into the characters’ personal lives, which mostly works, but it often slows narrative momentum while getting a tad too soapy — though that’s a minor complaint for such a great show.