The fascinating premise of “The Americans” — the FX series about Soviet spies hiding in plain sight, posing as a suburban couple during the Reagan-era years of the Cold War — didn’t fully coalesce in its first season. Yet the program did deepen its bench of characters as the year progressed, while upping the ante on its spy-counterspy espionage. A narrative high-wire act, the show remains eminently watchable, in part by pushing the sex-nudity-violence quotient about as far as any basic-cable series can. Nevertheless, it feels like this series comes with a built-in expiration date destined to kick in long before the Berlin Wall comes tumbling down.

The main challenge facing the producers as they seek new wrinkles in a story of constant deception and fear of exposure is in escalating the inherent cat-and-mouse game to levels of near-absurdity. Indeed, the central couple planted in the U.S. have gone beyond their double lives to triple ones, what with Philip Jennings (Matthew Rhys) having wooed a needy assistant in the FBI (Alison Wright) in an effort to secure intel from within the bureau.

Of course, there’s also the little matter of Philip’s often-tested arranged marriage to Elizabeth (Keri Russell), and the growing suspicions of their teenage daughter (Holly Taylor) about what mom and dad might be up to in their spare time.

Frankly, the most interesting thread took shape later in season one, involving Soviet embassy worker Nina (Annet Mahendru), initially compromised by an FBI agent (Noah Emmerich), who happens to be the Jennings’ neighbor, before coming clean to her superiors. Now, she’s acting as the agent’s mistress while working as a double mole, a plot thread with seemingly fewer logic-straining aspects than Philip and Elizabeth’s contortions to distract the kids when an assignment unexpectedly comes up.

Like most espionage tales, “The Americans” hinges on cultivating tension, with the built-in handicap that there are certain characters, presumably, who can’t catch a bullet (at least, not in a vital area). The show also straddles a delicate line, inasmuch as it forces the audience to identify with — if not necessarily root for — these Communist moles, who, despite their occasional misgivings and pangs of conscience, have registered no shortage of collateral damage in service to their cause.

Given that, series creator Joe Weisberg — who wrote the Thomas Schlamme-directed season premiere along with Joel Fields — and company have done about as well as is possible in keeping the plates spinning while adding new ones to the act. Even so, it’s hard to escape a sense that if this series runs much beyond a second season, it’s less about serving up art than it is about bowing to the needs of old-fashioned capitalism.

TV Review: FX’s ‘The Americans’

<p>(Series; FX, Wed. Feb. 26, 10 p.m.)</p>

  • Production: <p>Filmed in New York by Nemo Films and Amblin Television in association with Fox Television Studios.</p>
  • Crew: <p>Executive producers, Joe Weisberg, Joel Fields, Graham Yost, Darryl Frank, Justin Falvey, Daniel Sackheim; producer, Mary Rae Thewlis; director, Thomas Schlamme; writers, Weisberg, Fields; camera, Richard Rutkowski; production designer, John Mott; editor, Michael Berenbaum; music, Nathan Barr; casting, Rori Bergman. 60 MIN.</p>
  • Cast: <p>Keri Russell, Matthew Rhys, Noah Emmerich, Holly Taylor, Keidrich Sellati, Annet Mahendru, Susan Misner, Alison Wright, Richard Thomas</p>