‘The Diplomat’ season 4 review: Netflix’s addictive political thriller raises the stakes

Keri Russell leads a compelling ensemble as political backstabbing, moral uncertainty, and marital dysfunction make for a deliciously soapy fourth season of The Diplomat.

This review contains spoilers for The Diplomat Season 4.

Fail Marriage Fall has arrived, starting with Kate (Keri Russell) and Hal Wyler (Rufus Sewell), alongside President Grace Penn (Allison Janney) and Todd Penn (Bradley Whitford), before moving to George and Bertha Russell in The Gilded Age. Even Stuart (Ato Essandoh) and Eidra (Ali Ahn) aren’t immune to relationship troubles as The Diplomat returns for a fourth season fascinated with morality and loyalty.

Season 4 may be soapier than ever, but it’s no less entertaining. If anything, the political thriller has become even more addictive, though it feels less like a Netflix series made for binge-watching and more like a Sunday-night BBC drama, complete with shocking twists and dramatic cliffhangers that beg a week of theorizing.

That said, the binge model doesn’t necessarily weaken The Diplomat, and you’ll certainly appreciate being able to press play on Episode 2 after the premiere. Instead, the series offers a prime example of how streaming has lessened the anticipation between episodes, once one of television’s greatest pleasures. You can still theorize about what comes next, but where’s the fun when everyone watches at a different pace, and you can find out the answers to the questions Season 4 poses in a single sitting?

Diplomacy gives way to deception.

Picking up after Season 3’s nail-biting conclusion, Season 4 centers on the fallout from Grace and Hal’s covert operation to retrieve the Poseidon nuclear weapon from a Russian submarine in British waters. Kate, who convinced Prime Minister Nicol Trowbridge (Rory Kinnear) to sink the submarine carrying the doomsday weapon, finds herself cleaning up another mess her husband helped create.

What began as a calculated move to strengthen American security slowly but surely threatens to destabilize the country’s relationship with its closest ally. The consequences trigger a domino effect, forcing Kate to confront uncomfortable questions about the people she serves, including the man she married, and her own complicity in their decisions. Season 4 therefore explores how easily those in power justify dangerous decisions by convincing themselves they’re protecting the greater good.

Season 3 raised the stakes considerably, and although Season 4 takes its time escalating them further in relation to this plotline, The Diplomat remains a fast-paced political thriller packed with backstabbing, deception, and desperate attempts to maintain control. Episode 6 stands out, delivering a seismic twist that forces Kate into an impossible position. Stuart and Eidra’s willingness to challenge the decisions around them alongside Kate adds another layer to the season’s fascination with loyalty.

The finale rivals it in quality, bringing the season’s political and personal tensions to a climax. It’s an admittedly soapy spectacle, but one that shows how effectively creator, showrunner, and executive producer Debora Cahn can turn a trip to the G7 Summit into edge-of-your-seat television. She is, after all, no stranger to the genre, having written for The West Wing.

The Diplomat features one of television’s most underrated ensembles.

Like previous seasons, The Diplomat remains a compelling political thriller thanks to its ensemble, led by Russell, whose cutting line deliveries rank among television’s best. Russell makes Kate’s exasperation entertaining, whether she’s confronting a world leader as the US ambassador to the UK or arguing with her husband in her dual role as ambassador and Second Lady. But it’s the vulnerability she brings to Kate’s growing moral uncertainty that makes her Season 4 performance arguably her best yet.

Her chemistry with Sewell remains second to none. Kate and Hal’s marriage continues its cycle of reconciliation and threatened separation, with seemingly productive conversations about work or their personal lives frequently turning into arguments. Neither is ever on the same page, yet neither is willing to call it quits. They’re infuriating, though that is hardly a criticism; their dysfunction makes them even more compelling to root for, especially as Hal’s political ambitions further complicate their relationship.

Scenes between Russell and Janney are delicious. Neither performer backs down, and their confrontations, whether face-to-face or through a secure link, become gripping battles of wills. Throughout Season 4, Penn is more than willing to make the hard call, even when it could jeopardize the futures of both the United Kingdom and the United States. Russell matches Janney’s commanding presence with Kate’s newfound defiance, creating a fascinating power struggle between two women steadfast in their belief they’re doing the right thing, despite their different approaches to the cause.

A newcomer joins the ranks.

Jodie Whittaker is a welcome addition to the ensemble. She brings an icy yet personable confidence to her character, providing Kate with a new adversary who refuses to be intimidated by her American counterparts. Her confrontations with Russell are dizzying, with both actresses clearly relishing the opportunity to challenge one another. It’s a shame the season doesn’t make greater use of her, but this likely won’t be the last we see of the character.

Not everything works quite as well. The occasional unconvincing visual effect proves distracting, while some developments stretch credibility. Episode 1 ends on an effective cliffhanger, but its aftermath is underwhelming, prioritizing the season’s overarching political unrest over the intrigue its opening promises.

Similarly, a major reveal in Episode 3 happens solely to trigger fallout on both sides of the pond. Its consequences fuel a cast reshuffle that benefits the series but still feels random, briefly pulling viewers out of this season’s heightened worldbuilding.

The writing also reduces Todd to the role of the fool, especially when his attempts to understand his place in Grace’s life read more like a punchline than a legitimate storyline intended to develop his character. Todd and Grace may find themselves at a crossroads all season, but that does little to reduce the nostalgia-bait quality of their dynamic. Janney and Whitford’s shared West Wing history remains an undeniable part of their appeal, but the writing doesn’t always give Todd enough substance.

The bottom line.

The Diplomat remains one of television’s most compelling political thrillers, even as Season 4 occasionally favors spectacle over credibility. Its sharp dialogue, standout ensemble, and edge-of-your-seat twists make for nail-biting television, while its exploration of political power, loyalty, and moral compromise adds depth the series lacked in its first three seasons.

It’s a shame that The Diplomat doesn’t follow a weekly release schedule, but Netflix would be wise to stick to releasing a new season each year. With storytelling this addictive, there’s no reason it shouldn’t remain a regular fixture on our screens.

The Diplomat Season 4 premieres October 15 on Netflix. 

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Images courtesy of Netflix.