Toward the end of the most recent episode of the FX drama The Americans, which aired May 2, the married Soviet spies Elizabeth and Philip Jennings — played by real-life couple Keri Russell and Matthew Rhys — are once again at odds over whether the risks of their work are worth it. Elizabeth tells Philip she is going to Chicago to extract a fellow spy in trouble; she will risk anything for the cause she believes in, the Soviet Union.

Philip doesn’t want her to go, and instead wants her to come back and be part of their family Thanksgiving celebration. During the scene, the song “Ideas as Opiates” by the ‘80s pop group Tears for Fears plays, clearly substituting “ideas” into Marx’s famous saying, “Religion ... is the opium of the people.”

In 1962, the sociologist Daniel Bell wrote in The End of Ideology, “A total ideology is an all-inclusive system of comprehensive reality, it is a set of beliefs, infused with passion, and seeks to transform the whole of a way of life. This commitment to ideology — the yearning for a ‘cause,’ or the satisfaction of deep moral feelings … is a secular religion.”

Two decades later, with the Cold War at its zenith, the fictional characters in The Americans are waging their own war of ideas.

The Americans is, on the surface, a show about the ideological struggle between capitalism and communism, and how it affects protagonists on both sides. (It is also, as many critics have discussed, just as much about complex family dynamics — in this case, those of a family in which the parents are Soviet spies living in the U.S.)

However, as the show’s final season plays out, it’s increasingly clear that The Americans has also always been about political disillusionment — the weariness that comes from fighting for a system after seeing all of its flaws up close. The show is, in fact, a sharp critique of ideology and the effect it has on its disciples. Not only have we seen most of the primary characters go through a crisis of faith and question their commitment to their “secular religion,” but we’ve also seen some of them engage in treason, namely Philip, as well as the Russians living and working for the embassy in the U.S., Nina Krilova (Annet Mahendru) and Oleg Burov (Costa Ronin).

As the final season opens, showrunners Joe Weisberg and Joel Fields have jumped ahead three years to 1987, during the leadership of Mikhail Gorbachev, the Russian leader who advocated glasnost (“openness”) and perestroika (“restructuring”) policies to better position Russia to engage with the rest of the world. The changes led to internal dissension and infighting among the Soviets.

Correspondingly, in this season of The Americans, the U.S. is no longer the USSR’s only enemy; now there is a fierce internal struggle between reformers and hardliners. Philip and Oleg, along with Arkady Zotov (Lev Gorn) — the former Russian ambassador to the U.S. who is now home, working for the government — are on one side of the struggle, supporting Gorbachev’s agenda of dialogue with the U.S. On the other side are Elizabeth and “the Center” — represented by her boss, Claudia (Margo Martindale), and Claudia’s boss, Tatiana Vyazemtseva (Vera Cherny) — who cling to old-school Communist orthodoxy and work against their own leader’s reformist agenda.

Matthew Rhys and Keri Russell in FX’s ‘The Americans’ FX Networks/IMDb

Ideological disillusionment was a major theme in the show’s fifth season that touched all of the show’s protagonists. Stan Beeman (Noah Emmerich), the FBI agent who lives across the street from the Jennings and has been working to catch Russian spies, decides in season five that he is unwilling to carry out the FBI’s ruthless methods if it means hurting Oleg, a Russian with whom he’s built a relationship. Stan threatens to create a public scandal for the FBI — by admitting publicly that he killed a Russian citizen — if the FBI goes after Oleg, effectively torpedoing his career as a counterintelligence agent to protect someone who’s supposed to be “the enemy.”

Oleg’s disillusionment with the Soviet system was a parallel storyline last season, as he came to realize while working in an anti-corruption unit of the government how corrupt the system actually was: He saw low-level black-market operators targeted and imprisoned, while higher-ups with important Communist Party connections were protected.

This season, Oleg’s disillusionment has continued — he’s now actively working to subvert the hardliners — but Stan’s has reversed course. After two of his sources are killed by Russians, he once again believes in the righteousness of the American cause. His speech in the most recent episode, around the Thanksgiving dinner table, shows his renewed commitment: “Not everybody around the world wants us to live in peace and freedom. … There are people out there who don’t like our way of life. They are afraid of it.”

Explicitly ideological statements are a rarity in The Americans, which thrives on subtext. So Stan’s speech calls to mind Elizabeth’s retort to Philip in episode three of this season, when he suggests the arms summit between the U.S. and Soviet Union is a positive step: “All this talk of perestroika and glasnost. They eat it up. The Americans want us to be just like them. … I don’t want to be like them.”

In fact, this season, Elizabeth is as rigid and devoted to her secular religion as ever — one of the few characters who isn’t becoming disillusioned with her ideology, though its negative effects on her life are a sign that it’s still causing great damage. In the still-unfolding sixth season, Elizabeth is exhausted and her body count is mounting.

Keri Russell in the final season of FX’s ‘The Americans’ FX Networks/IMDb

In almost every episode, Elizabeth kills people she isn’t sent to kill: the naval officer who pesters Paige during one of her first missions with Elizabeth; General Rennhull, the U.S. military official who actually once helped Russia, but refuses to spy again; the warehouse worker whose girlfriend might have blown Elizabeth’s cover; several warehouse employees during her botched break-in; and most gruesomely, Sofia, the defector who had just been granted asylum in the U.S. For a moment, there’s even the possibility she’ll kill Sofia’s young child if he sees her face; what’s chilling is that we know she would do it for the sake of the cause.

Elizabeth’s ideological rigidity isn’t just taking an enormous toll on her body, it’s also bringing out her mean streak and effectively destroying her family. The spectacular, arresting fifth episode of this season sees her manipulate Philip into sex to ask him to do something she knows he’d be loath to do (use a longtime asset, Kimmy, as a pawn to extract information from her CIA agent father). She later accuses Philip of sleeping with Kimmy because he wasn’t getting enough action at home, though she knows he had avoided sleeping with Kimmy in previous seasons, and that he’d only initiated sex to help Elizabeth with her mission.

In this season’s sixth episode, when another “illegal” spy has been discovered by the FBI in Chicago, she tells her husband she will be the one to go help extricate the other spy, regardless of the risks to her or her family: “One of us is in trouble in Chicago, Philip. I’m going there to help him. Someone who’s still doing his job. Someone who still gives a shit.” And there it is: Despite Elizabeth’s claim to support Phillip’s decision to quit the spy game, there’s still a part of her that resents him for not prioritizing Mother Russia over all else.

Similarly, Elizabeth no longer sees or treats Paige as a daughter or has a relationship with Henry, their son. Elizabeth treats Paige only as a spy-in-training, as evidenced when she tears into Paige for “leaving her post” when Paige was clearly worried about her mom after hearing gunshots during the meeting with Rennhull. Philip, on the other hand, can only see Paige as his daughter, and continues to believe it was the wrong decision for her to follow in her parents’ footsteps. In an intensely emotional scene in season six’s fifth episode, Philip challenges Paige to a physical fight to see what she’s learned; he’s smoldering with suppressed rage, wanting nothing more than to literally knock some sense into his daughter.

It’s not only Philip’s ideological commitment to Russia that wavers. This season, he has begun to see the dark side of capitalism as well, as his decision to expand the family business, a travel agency, has backfired: His clientele hasn’t grown in proportion to his investment, he can no longer pay for Henry’s boarding school and he’s forced to lay off several longtime employees. Tellingly, the season’s fourth episode ends with a flashback to his childhood in the USSR, with him and other kids lining up for scraps, literally licking the pan to get enough food. His trauma about going hungry as a child still lies just beneath the surface, and the cut-throat free market system is triggering it.

There were moments, in earlier seasons, when Elizabeth’s vulnerability cut through the tough exterior and it seemed she might follow Philip’s lead. The memorable season three episode, “Do Mail Robots Dream of Electric Sheep?” saw her soften and confess her real identity to an old woman who reminded her of her mother but who she knew she had to kill. And, as highlighted by critic Angelica Jade Bastién, she has sometimes forged true friendships with female assets, such as Young-hee in season four, that have made her missions incredibly hard to stomach.

Up until the last few moments of season five, Elizabeth was ready to turn in her wigs and disguises along with Philip, but ultimately she was pulled back in by her unshakeable duty to the motherland. In this final season, it’s clear that Elizabeth’s family (and her own life, as she’s now carrying around a suicide pill) are expendable, all for the sake of a system that — as Oleg has realized — is rife with corruption. She stands as the lone character who continues to believe, at all costs, in her secular religion.

The Americans has always used music incredibly effectively, sometimes as a substitute for dialogue. Two songs in particular this season make clear the writers’ skepticism about ideological absolutism: Peter Gabriel’s “We Do What We’re Told” from the season premiere and “Ideas as Opiates” by Tears for Fears from the most recent episode, discussed earlier.

As the writers are suggesting both with these songs and the arcs of the main characters, it’s not only organized religion that can be dangerous, but also, as Bell describes ideology, “secular religion.” With only four episodes left, we still don’t know if the “true believers” of The Americans are going to make it out alive — hell, we still don’t even know if Stan’s new wife, Renee, is a spy! As a historical drama, one thing is certain, though: Elizabeth is fighting for a lost cause, a beautiful idea (socialism) that has ultimately been corrupted by the abuse of power.

However, if we take the series as a whole, it’s plausible that the show will also leave us with an indictment of the imperialist, interventionist ideology of the U.S. While history books state that the U.S. won the war of ideas, in The Americans, virtually everyone loses faith.