The big bad bear from Moscow is back, and not just in Crimea. FX's "The Americans," about deep-cover KGB "illegals" living in Washington, D.C., in the early 1980s, is now midway through its second season. There's much to like about the show, from top-notch performances by Keri Russell and Matthew Rhys, to their reliance on clunky, retro-spy technology, to the clever manipulation of a common fear felt, no doubt, by most children at one point or another that their parents have secret identities (it ain't paranoia if it's true).

But I was in the intelligence business, too, and a fundamental part of the series irks me. Even though the CIA hired me after the 9/11 attacks to fight a new menace — terrorism and Islamic extremism — the corridors at Langley still echo with the footsteps of old-timers who recall the protean fight against the Soviets. And regardless of how that conflict is portrayed in Joe Weisberg's captivating series, it was not a sequence of increasingly lethal encounters between U.S. and Russian intelligence services.

To be sure, much about the show is based on reality. The premise — that Russian spooks were living double lives in the suburbs — was inspired in part by a real-life network of Russian illegals (made famous by the bombshell Anna Chapman) that was busted by the FBI in 2010. Then there is the series of background events — the assassination attempt on President Ronald Reagan, Alexander Haig's controversial statement that "I'm in control here" — that situate the drama on an authentic historical timeline.

But "The Americans' " fidelity to fact often ends there: The KGB certainly ran significant intelligence-gathering operations during the Cold War — and even carried out "dirty tricks," like organizing a racist letter-writing campaign, purportedly by American white supremacists, against African diplomats at the United Nations, and desecrating American synagogues and Jewish cemeteries to stir up discord and prove that the United States was a lousy place to live.

At the end of the day, however, the KGB never actually killed anyone in America. Washington was a violent place back in the Reagan years, but not because Russian spies were murdering folks left and right.

After all, killing people — like the security guards, former assets and random civilians that bite the dust in "The Americans" — in pursuit of intelligence is fraught with danger. Political murder would not only have focused America's domestic security apparatus onto Soviet affairs like a laser, it would have also threatened bilateral relations — with potentially devastating consequences. For instance, when U.S. government contractor Raymond Davis shot and killed two thieves on a Lahore street in 2011, the incident touched off a massive diplomatic row that threatened to upend an already-strained U.S.-Pakistan relationship. If the Soviets had behaved similarly on the streets of Washington during the height of the Cold War, they could have set off a massively destabilizing tit-for-tat escalation.

It should come as no surprise, then, that Cold War espionage involved more dead drops, covert meetings and brush passes than brazen assassination attempts. In fact, there's only ever been one assassination of a Soviet defector in D.C. — in 1941 at the Bellevue Hotel, and it may have actually been a suicide. If Stalin's genocidal People's Commissariat for Internal Affairs, or NKVD, could only muster one possible killing in America, Leonid Brezhnev and Yuri Andropov's KGB would not have dared.

So what were these Soviet illegals actually doing in the suburbs? Probably not too much, according to retired KGB Maj. Gen. Oleg Kalugin, who wrote in his memoirs that the deep cover agents were the "least productive" of the KGB's branches working in the U.S. capital. The most recent batch of busted Russian deep-cover agents apparently only managed to collect open-source material during their stay in America — information that could have been discovered by anyone with Internet access. In fact, the U.S. Justice Department didn't charge any of them with espionage because they never actually sent any classified information back to Moscow. It wasn't exactly the stuff of a Robert Ludlum thriller.

Nor were American spies the kind of cowboys portrayed in "The Americans." Spoiler alert: Much of the first season revolves around how the members of an FBI counterintelligence unit begin to take their jobs so personally that they try to kill a top KGB official at the Soviet Embassy, spurred purely by revenge. Even more incredibly, an American assassin manages to take out a KGB general in his Moscow apartment. Sure, there was plenty of skulduggery in the 1980s, but killing diplomatically protected individuals in America is a bridge too far. And sending assassins to Moscow to kill KGB officials is pure lunacy.

The reality is that it's far more practical to swap compromised assets for American human assets caught behind enemy lines. After all, that's what the FBI has traditionally done, monitoring real-life illegals like Anna Chapman before arresting and swapping them for compromised Russian personnel who were secretly working for the United States.

Finally, there was an unspoken understanding about reciprocal behavior between the United States and the Soviet Union, especially during the era of "The Americans." Even abroad in hot wars like 1980s Afghanistan, there were general rules about taking lives. As Steve Coll noted in his book "Ghost Wars," "The CIA and KGB had settled during the 1980s into a shaky, unwritten gentlemen's agreement that sought to discourage targeting each other's salaried professional officers for kidnapping and murder." This went beyond professional courtesy: Intelligence officials understood that the tables could be turned in another battlefield. Whacking KGB officers in Kabul could get CIA personnel bumped off in, say, Managua.

With U.S.-Russia tensions on the rise over Ukraine, Syria and elsewhere, the bogeyman from Moscow in "The Americans" feels ripped from today's headlines. But by portraying an increasingly baroque series of killings as a proxy for effective intelligence gathering, the series stays firmly in the world of entertainment. To be fair, Weisberg has always been open about his disappointment with the banality of real intelligence work. A CIA employee for a brief period in the 1990s, he decided he'd rather write about spies than be one. For those of us with experience in the shadowy world of intelligence, however, "The Americans" is a little too good to be true.

Aki Peritz is a national security adviser at Third Way, a Washington-based think tank, and a former CIA counterterrorism analyst. He is author of "Find, Fix, Finish: Inside the Counterterrorism Campaigns That Killed Bin Laden and Devastated al Qaeda." He wrote this article for Foreign Policy.