The Diplomat Season 4 Ending Explained: Hal's Next Move & What It Means For Season 5

Published Oct 15, 2026, 2:31 PM EDT Angel Shaw is a Lead Writer and Critic on ScreenRant's TV team, covering new-release and classic TV shows across all major streaming platforms. She has been a writer with ScreenRant since 2022 and specializes in Harry Potter, The Lord of the Rings, and fantasy. Angel holds a bachelor's degree in language interpreting and is passionate about all things culture and communication—especially in how it relates to popular media throughout history (from Shakespeare to Friends to Game of Thrones). Warning! Spoilers for The Diplomat season 4 ahead!Netflix's The Diplomat has given us another explosive ending, making the events of a potential season 5 completely impossible to predict. This political drama is known for its shocking twists and turns, and it always manages to sneak one in just before a new installment comes to a close. That was certainly the case for The Diplomat season 3, which concluded with the reveal that Grace Penn (Allison Janney) and Hal Wyler (Rufus Sewell) stole Russia's Poseidon missile. It's also the case, of course, for The Diplomat season 4, which carries that twist further. The Poseidon theft remains a key detail throughout The Diplomat season 4 as Kate Wyler (Keri Russell) fights tirelessly to keep the UK from discovering the truth. That becomes nearly impossible when she realizes that the cover-up plan to bury the Russian sub with concrete, allowing the Brits to believe the Poseidon is buried with it, falls apart. The US forgot to pretend that its budget was supposed to account for the encapsulation of a doomsday weapon, not just a harmless old sub. Ultimately, Hal has to let the cat out of the bag, and that's the beginning of the end. Hal's big moment of truth sets off a snowball effect that ultimately leads to Trowbridge's resignation and the election of a new Prime Minister, who has no interest in telling Russia it can't come to retrieve its lost sub. Penn finds that unacceptable, and when Kate refuses to threaten acts of war against the UK, she has her husband, Todd Penn (Bradley Whitford), do it instead. That brings us to the ending of The Diplomat season 4, which sees President Penn make her threat against Prime Minister Bethan Vaughan (Jodie Whittaker) crystal clear by announcing it publicly at the G7 summit. The US will fire on any country that gets in the way of keeping Russian warships out of the European seas. It's extreme and terrifying, which is precisely why Kate, followed by Billie (Nana Mensah) and Ganon (Miguel Sandoval), publicly resign and walk out. What's even more shocking than this move, however, is that Hal walks out too. Was Hal's Walkout Really The Right Move At The End Of Season 4 Of The Diplomat? Much of The Diplomat season 4 was dedicated to the idea that Hal and Penn are two sides of the same coin. Together, they are a powerful force, but that also makes them extremely dangerous. Penn is all too willing to carry out what she deems necessary evils (as we saw with the HMS Courageous in season 1 and the Poseidon in season 3). At the same time, Hal has an impossible time resisting power and influence. Even Kate seemed to assume when she kissed Hal just before publicly resigning at the G7 summit that he wouldn't follow her. We see the relief on Kate's face as she turns to see Hal exiting the building behind her in The Diplomat season 4's final moments. She didn't expect her husband to walk away from the POTUS, but she is clearly happy that he did. From there, it seems Kate and Hal are immediately on the same page. Kate tells the press that Hal has something to say, and, without missing a beat, he begins. Of course, we don't yet know what Hal actually tells them. The important thing here is that The Diplomat's Vice President of the United States just publicly pitted himself against the POTUS, or he may have resigned entirely. It certainly made a statement, especially since it will be clear to all exactly why President Penn has lost so much of her support. However, the tricky thing is that this walkout by no means removes Penn from her position of power. In fact, as VP, Hal can formally question Penn's ability to serve as POTUS. If he has resigned or publicly denounced her, Penn will either nominate someone to take his place or begin her own efforts to push him out of office. It's all out on the table. Everything Depends On What Kate & Hal Tell The Press In Season 5 This explosive situation at the end of The Diplomat season 4 raises an intriguing question. Kate long believed that, as a diplomat, she could temper the dangerous decisions of those in power around her. She used her clever mind to manipulate (to put it harshly) the likes of Trowbridge, Grace, Hal, and so on. However, in season 4, Kate came to see that she was the one being influenced. She had given in to corruption, and unless she walked away, things would only get worse. Hal has now done the same thing, but is that taking it a step too far? The ending of The Diplomat season 4 questions whether good people should play along with corrupt leaders in hopes of balancing out their worst impulses or overtly demonstrate their descent by refusing to participate. The answer, as far as this fictional series goes anyway, will come down to what Hal and Kate say to the press as The Diplomat heads into season 5. After all, the Wylers essentially just gave up all of their overt political power. The only influence they have now will rest with how the public responds. The Diplomat Could Be A Very Different Sort Of Show In Season 5 If Hal hadn't followed Kate out of the building in The Diplomat season 4, season 5 likely would have seen the Wylers working behind the scenes to challenge Penn's competence as president. It's within Hal's power as VP to begin this process with the Cabinet, but if he truly resigned, then this is no longer an option. This ultimately means the Netflix series will continue with a very different dynamic one way or the other. The Diplomat will no longer be about a diplomat, an ambassador, or anything similar. Kate might still be the Second Lady, but even that seems unlikely. It will be interesting to see how The Diplomat maneuvers itself if its central characters aren't actually in government anymore. We can naturally assume that neither Kate nor Hal will resign to a quiet life. They are both too passionate about (and frankly, addicted to) the world of politics for that. However, their general influence will be a whole lot trickier. Meanwhile, President Penn continues to hold immense power, and there are even fewer people in her circle to check those worst impulses. We are certainly in store for another thrilling season of The Diplomat. Release Date October 14, 2026 Network Netflix Series The Diplomat Episodes 8