Matthew Rhys and Keri Russell as Philip and Elizabeth Jennings, the KGB agents posing as normal marrieds in the Northern Virginia suburbs. (Eric Liebowitz/FX)

Although the FX series “The Americans” has been praised for its nuance, it creates a cloak-and-dagger world where tools never fail, master plans almost always work out and the best spies always win.

Real spies know that world is make-believe. Still, when they’re done lurking in shadows — or typing away in their cubicles, more likely — they often come home and turn on the show about Soviet sleeper spies (Matthew Rhys and Keri Russell) posing as a married couple, which returns for a fourth season on Wednesday. Spies recognize that the show exaggerates, but they also mostly praise the ways in which it rings true — and even the ways it doesn’t.

“It’s kind of an open secret that many people in the intelligence community are some of the most avid readers of spy novels and most avid watchers of spy shows and movies,” says Doug Patteson, a former CIA officer with extensive overseas experience, now living in New Hampshire. “It gives you this idealized view of the intelligence world that’s very different from the practical aspects of day-to-day life. The truth is that often, real-world intelligence can be a bore, a drudgery.”

Emily Brandwin is a former CIA officer in Los Angeles. She appreciates escapism as much as the next person, but when it comes to espionage, she watches with a critical eye. Kiefer Sutherland’s Jack Bauer? He’s escaped death way more than real spies, who mostly never see action. “Homeland” gets a lot right, although Carrie would have never been hired due to her multitude of emotional issues.

Then there’s “Alias,” filled with outrageous, campy costumes. “I go: ‘Why can’t I look like Sydney Bristow?’ You see her and she’s scaling down a building in a black catsuit and a hot wig and she looks amazing,” Brandwin says. “And here I am with a bad wig and a pregnancy belly and I look horrible.”

But “The Americans” has won Brandwin over. “There are such nuggets of authenticity that you don’t see in other shows. Everything from gadgets to surveillance is done with great care and authenticity, and you can feel that it’s not over the top, it’s really core to the characters,” she says.

After all, the series’ creator and co-showrunner Joe Weisberg has firsthand experience. Lured in by the spy world of John le Carré novels, Weisberg spent 3 1/2 years working for the CIA.

The series is often praised for using authentic tradecraft. That was the relatively easy part.

“The thing [that interested me] about espionage wasn’t so much about stealing secrets or operations per se,” he explains. “It was about the lives of officers and how they felt.”

Weisberg was fascinated by the idea that intelligence officers lie to their kids about what they do and one day might have to confront them with the truth. That human side, to him, made it the drama special. “Can you take the spy out of it, and still make it work?” he says.

Leading a dual life can have a real tension on relationships. “The reality of espionage is that, yes, some of it can be exciting, but it can also be a very dark, very lonely job,” says Brandwin, who had to maintain a cover identity for her friends and dated fellow CIA officers. “When you’re trained to be a professional liar and you’re dating other trained liars, it is a very bizarre thing.”

Before becoming a field officer, Brandwin began her career in the CIA as a disguises officer. (Yes, that’s an actual position.) “What I really appreciate is that the disguises are never a joke, it’s really a part of how the characters pull off their operations, so it’s essential,” she explains about the series. “It’s not just about someone slapping on a wig, but the care and details of crafting a persona every day.”

In one scene, Martha, an FBI secretary that Rhys’s character’s alter ego, Clark, seduces to glean information, observes that he is wearing a toupee. Clark thinks his cover may be blown, but he soon realizes that Martha attributes the hairpiece to vanity and hair loss, not a faux identity. She doesn’t question Clark’s authenticity, because the rest of his disguise is so complete, such as his nerdy, slightly nervous manner of speaking.

But the show doesn’t get everything right. “The murder and mayhem on the show is probably more the Hollywood part of it,” Brandwin says.

“Violence leaves forensic information and can be seen by witnesses, increasing the risk of detection,” Patteson says. “It’s great for the storyline but would never happen so frequently to such valuable assets as these two illegals. In the real world, if you get involved in a violent incident, you are likely on the first plane home.”

Illegals, a term used for Russian sleeper agents, would also not be likely to be used so much in real life given that they are expensive to train and run. “The more you use them, the higher the risk of exposure — the more you risk your investment,” says Patteson.

Accuracy aside, pop culture depictions of espionage have long helped recruit new spies. “Lots of people who joined would say that the thing that got them intrigued with the intelligence community was James Bond or Jason Bourne or a good novel or a good show,” Patteson says.

And some aspiring spies have even taken some valuable lessons from these on-screen depictions. Naveed Jamali, for instance, maintained his normal life while working from 2005 to 2009 as a double-agent for the FBI to help bring down a Russian spy ring in New York. (His story has become a book and soon-to-be movie, “How to Catch a Russian Spy.”)

While training to be undercover, he used Bourne, Bond, George Smiley, “Magnum P.I.” and Michael Mann characters as role models, plagiarizing their mannerisms and dialogue. “The way I protected myself is by using movies and TV to build a character that [I was] comfortable with,” he says.

Jamali also says that on “The Americans,” the reasons the characters go into spying feels true to life. In Season 2, Andrew Larrick, a Navy SEAL and a closeted gay man, becomes vulnerable to blackmail by the Russians and is forced to spy for them. And last season, Lisa, a struggling single mother and recovering alcoholic, agrees to trade information gleaned through her security clearance in exchange for money. The show “gets the motivation of those characters down very, very well,” he says. “It’s a very difficult line between duty for your country and self-preservation.”

The reasons people become spies are often the same reasons why people love watching them — and why espionage is often jokingly referred to as the second oldest profession. People are always “wanting to know secrets and share secrets and [there’s] this belief that there is this master plan being executed by somebody just so that it can explain the madness of it all out there,” explains Patteson. “That all appeals to these aspects of people’s psyche and draws them in.”