‘The Diplomat’ season 4 trailer teases political and marital tensions

By Andrea Tuccillo Sep 15, 2026 | 3:30 PM

Keri Russell as Kate Wyler, Rufus Sewell as Hal Wyler and Allison Janney as Grace Penn in episode 1 of ‘The Diplomat’ season 4. (Netflix)

Fresh off of Allison Janney’s Emmy win for her supporting role in The Diplomat, the Netflix series has dropped its first full-length trailer for season 4.

The clip finds Keri Russell’s Kate Wyler as she struggles to trust her husband, Rufus Sewell’s Hal Wyler, who’s now vice president to Janney’s President Grace Penn. At the end of season 3, Kate realizes Hal and Grace conspired together on a mission with dangerous risks to global security.

“One catastrophic moment shatters the fragile peace Kate Wyler brokered between the US and UK, as well as the crumbling marriage she’s trying to save,” reads the logline for season 4. “While she fights to stem the bleeding, President Grace Penn and VP Hal Wyler’s conspiracy to steal Russia’s most powerful weapon hurtles the United States toward war.”

The Diplomat was a 10-time Emmy nominee this year, including a nod for outstanding drama series and acting nods for Russell and Sewell.

The series also stars Bradley Whitford, Ato Essandoh, Ali Ahn, Nana Mensah and Rory Kinnear.

Season 4 debuts Oct. 15.