Tonight marks the premiere of FX's next big show (or at least they hope it's big), The Americans. It's a concept-heavy espionage drama about undercover Soviet spies (Keri Russell and Matthew Rhys) posing as regular Jane and Joe Suburbia in the early 1980s. And while on paper it sounds like a thrilling concept — Homeland meets The Riches meets Alias — in practice The Americans, based on the two episodes I've seen, is so far an inert and tonally imbalanced effort, too thrilled with its own concept at the expense of execution.

Russell and Rhys play Elizabeth and Phillip Jennings, not their real names of course, but ones they've assumed over a decade of living, accent-free and under the radar, in the D.C. suburbs. We first see the couple when they are on a mission to apprehend a KGB officer who has defected. It's a dark night on the city streets, a twangy guitar plays a fast tune, and there's a bout of martial arts-inflected fisticuffs in a shadowy alleyway. This opening scene is an immediate indication that this particular Cold War spy story is not going to be some John le Carré-style quiet thriller of manners and small gestures. There's muscle here, and butts are thoroughly kicked several times in the first two episodes. There's nothing wrong with butt-kicking, several current spy shows do it quite well, but when The Americans is also trying to be a nervy, intelligent drama about secret lives, all the action plays a bit silly.

The Americans chiefly suffers from a credibility problem. We might be better able to get past the alienation of already knowing how the Cold War ends if the show's mechanics were crafted more carefully, but as is, most of the covert ops register as a goofy game of pretend. That Elizabeth and Phillip, who were fashioned into a couple by the KGB in the mid-1960s, have two children now is supposed to add texture to their deep-cover identities, and perhaps some real-life secret Soviet spies did get so ensconced in their fake lives. But in the world of the show, the children play only as a tremendous nuisance and egregious potential threat. Why would the Soviets send two young people to live with the enemy for years and then order them to breed more of the enemy, thus confusing the sides for their two valuable assets? Elizabeth and Phillip obviously love their children, if not necessarily each other, but Elizabeth at least still talks of "the Motherland" and dying in the name of duty. Phillip, on the other hand, seems to want out right away, right there in the pilot episode, sapping any dramatic potential that could have been built up over the course of a season. The matter of the children and the allure of the comfortable trappings of American living are supposed to create tension — do the Jennings stay loyal to the task bestowed upon them like a holy mission, or do they run away into their new pretend life? — but they read as hokey contrivance. Perhaps when we get to know these characters and their motivations a bit better, this push and pull will make more sense, but barely anything beyond the most basic of traits — she is dedicated, he is wishy-washy — has been established by the end of the first two hours.

There's also the matter of the missions the pair is sent on, far too daring bits of Bourne stuff that involve silly wigs and fake mustaches. I don't know how much research was done to tell this story — or how much could be done, given the clandestine nature of the subject — but it seems dubious that the real deep-cover Soviet plants were running around college campuses and apartment buildings with fake hair spirit-gummed everywhere. In one particularly ludicrous scene, Phillip goes on a terrifically risky extracurricular jaunt to beat up a gross thug who hit on his young daughter at a department store. But it's OK! He's not at risk of exposure, because he's dressed up like George Harrison. And while on the topic of eyebrow-raising contrivances, must the new counterintelligence F.B.I. superstar (Noah Emmerich) have moved in right next door to the Jennings? At least on Breaking Bad uncle Hank lives across town.

The show's other chief sin is that no one is particularly likable. Russell, like Homeland's Claire Danes, here has a chance to reinvent her TV career, to shed the curly-haired flightiness of her Felicity days and bite into something deep and obsessive, and grownup. She does a fine, suspiciously well-clothed job with what she's given, but her role is underwritten. Watching her struggle to sell lines in which Elizabeth gently defends the Soviet space program to her son or bluntly criticizes Reagan is distressing. We're supposed to like Elizabeth because she's human and conflicted, while I guess we don't like her American foes because of Reagan? I'm not sold. These are Soviet spies we're talking about! No one is saying that a morally complex character can't be a compelling series lead -- I think it's brave and ambitious of FX to attempt just that -- but the show needs to spend less time on lazily drawn equivocation and more on establishing motive so that we at least have something to grab onto, for good or bad. Meanwhile Rhys is a mostly charmless performer, awkward and struggling with his accent. He's a Brit playing a Russian pretending to be an American. That might sound like a casual Sunday stroll for Meryl Streep, but Rhys is overwhelmed. His character is also too rushed — we've seen him go through about four stages of second-guessing and hand-wringing by the end of the second episode -- and he's not good at playing the frantic beats. Whatever happened to the slow burn? The writers are so eager to get us addicted to this thing, to make it the next buzzy water-cooler hit, that I guess they figured they'd throw the entirety of the show's conflict at us right away.

The Americans isn't quite soapy, isn't quite sexy, and is not terribly exciting. I'll be sticking with the show for a little while because I think the premise is strong and might prove fruitful with a few tweaks. (And because Margo Martindale is joining the cast soon.) Maybe send the kids off to boarding school, have the Jennings move to a non-F.B.I. neighborhood, and slow the pace down. We don't need all this running around, punching and kicking, to get excited. As much as the show rests on the laurels of its inventive conceit, it doesn't seem to know what to do with it. It's a confusing world, to be sure. But you're professionals! Figure it out. Otherwise, I'll soon be saying do svidaniya and finding a rerun of Boris and Natasha to watch instead.