Keri Russell and Matthew Rhys photographed on the set of “The Americans” in Brooklyn last year. (Marvin Joseph/The Washington Post)
Opinion writer

This post is a backward-looking tribute to “The Americans,” rather than a review of the show’s new season. If you want to know nothing about the new episodes, and have watched through season five, read on in confidence.

When “The Americans,” FX’s period drama about a married pair of KGB spies working under deep cover outside Washington during the terminal years of the Soviet Union, premiered in 2013, it had all the hallmarks of a typical Golden Age show. Its main characters, Philip Jennings (Matthew Rhys) and Elizabeth Jennings (Keri Russell), juggled respectable identities as suburban travel agents with their real work as seducers and assassins, even as they befriended the FBI agent across the street.

But unlike other series, in which the transgressions of middle-aged men like Tony Soprano (James Gandolfini) and Walter White (Bryan Cranston) gave audiences a naughty thrill, the Jenningses’ exploits were freighted with sadness and an escalating toll of moral responsibility. Instead of journeying further into their alter egos, Philip and Elizabeth were carried into deeper communion with their authentic selves, no matter how hard or how long they may have tried to suppress them.

These qualities have long made “The Americans,” which begins its final season on Wednesday, one of the most humane shows on television. And although the show’s portrait of the Cold War carries some superficial relevance in an age of escalating tensions between the United States and a Russia dominated by a man eager to avenge the humiliation of the Soviet Union’s defeat, that’s not why “The Americans” feels so essential today. Rather, the series is an argument — and a vital one in a polarizing time — that ideology isn’t the sum total of a life. Our dogmas will not save us.

On its most obvious level, “The Americans” is about marriage, and about all the compromises, communication and hard work that go into making one work. Marriage is an essential part of a fulfilled life, though it’s hardly the only one. And as outstanding as “The Americans” was in its first season, when it focused on the transformation of Philip and Elizabeth’s marriage from a strategic sham to a genuine romance, it became even richer and more moving in subsequent years, as it examined the characters’ broader quests for fulfillment and enlightenment.

For each member of the Jennings family, that path was different, though their thoroughfares often led them in surprising, even looping directions.

In the first season, Philip’s initial fondness for cowboy boots and American cultural and consumer ephemera seemed like a weakness. His later involvement with Erhard Seminars Training, one of the self-improvement movements of the ’70s, made him a more emotionally integrated person and a better husband. Philip’s new closeness with Elizabeth helped make their relationship a genuine partnership, rather than a mere cover, culminating in their decision to solemnize their marriage in the fifth season of “The Americans.” But the warmth of their romance also made it harder for them both to carry out the kind of honey traps that had previously been a routine part of their profession.

Elizabeth, by contrast, tended to stumble on avenues of self-exploration through her work. Her friendships with Mary Kay saleswoman Young Hee Seong (Ruthie Ann Miles), her wary engagement with Pastor Tim (Kelly AuCoin) and his wife, Alice (Suzy Jane Hunt), and her professional pursuit of Ben (Brett Tucker), a health-food-shopping, tai-chi-practicing idealist who wants to end world hunger, all unthaw Elizabeth, at least temporarily. She’s supposed to steel herself to do her work, but by design, spying brings her into contact with more of the United States and more Americans than she ever would have encountered if she had stayed safely inside the ideological bubble of the Soviet Union.

Like their parents, the Jennings children are searchers. Paige’s (Holly Taylor) conversion to Christianity brought her to Pastor Tim’s socially engaged church, where Tim himself ended up encouraging her to read Marx and provided her with the perspective that made her receptive to her parents’ revelation about what they do for a living and their reasons for doing it. And Henry (Keidrich Sellati), largely left to his own devices both by his parents and by the show to an extent that became something of an in-joke, found himself in academic achievement and ended up gravitating toward a privileged boarding school milieu, and toward Stan Beeman and the FBI — toward a version of the American establishment that faced its own existential threats in the 1970s and ’80s.

The most important argument “The Americans” makes, and the one that’s most sharply relevant to our current political moment, is that ideology can’t meet all your emotional needs, nor will it protect you from making grievous mistakes as you struggle to navigate your intimate life and shape your self.

Giving Philip and Elizabeth Jennings some paperwork didn’t make them married, and their mission was not a substitute for an emotional life. Learning to fight helped Elizabeth recover from the rape she experienced in training, but it didn’t save her from being raped in the first place. Giving Philip a substitute wife and a new family didn’t prevent him from being shocked when he learned about the existence of the son he’d fathered as a young man. Christianity does not resolve the conflict that Paige feels between her family and her attraction to Matthew Beeman (Danny Flaherty).

Being an agent of the Federal Bureau of Investigation may mean that Stan Beeman is expected to be a paragon of virtue. But a badge and a dark suit are not automatic guards against sexual temptation. Nor, as Stan discovers when his wife, Sandra (Susan Misner), leaves him, is the appearance of rectitude the same thing as private happiness. And it becomes increasingly difficult for Stan to substitute the bureau’s decisions for his own conscience as he comes to know Soviet citizens like Oleg Burov (Costa Ronin) and comes to accept that neither of their nations has a monopoly on goodness.

“The Americans” doesn’t suggest that ideology is unimportant. By contrast, it shapes its characters’ entire lives and defines an epochal struggle for the fate of the world. Gabriel (Frank Langella), the Jenningses’ courtly handler, has given himself entirely to his work, treating his charges like a surrogate family. Martha Hanson (Alison Wright), an FBI secretary who makes the mistake of getting involved with Philip in the guise of one of his alter egos, is swept off to the Soviet Union and forced to abandon her entire life and family by the mechanisms of the state.

The Soviet and American systems may inspire incredible, even fanatical loyalty. They may grind up the people who devote their lives to the struggle. But if “the problems of three little people don’t amount to a hill of beans in this crazy world,” as Rick Blaine (Humphrey Bogart) put it in “Casablanca,” “The Americans” also proves that ideology and politics are insufficient to solve the dilemmas of the human heart.