The two best friends that anybody could have. Photo: Jerome Delay/AFP/Getty Images

It’s all been leading up to this. Since the beginning of its final season, The Americans has been teasing us about an upcoming summit, and this week, it’s finally here: In “The Summit,” Soviet leader Mikhail Gorbachev will visit Washington, D.C., for three days of face-to-face meetings with U.S. president Ronald Reagan. (Spoiler alert: They both survive.) As Vulture’s official history explainer, I’ll fill you in on exactly what you need to know about the 1987 conference.

Okay. So I know there’s a summit and it’s a big deal, but I haven’t quite grokked exactly what’s at stake.

Everything’s at stake! This is the Cold War — nuclear devastation, mutually assured destruction, the president going head-to-head with the leader of the Soviet Union in a high-stakes game of international diplomacy!

Yes, I’m watching The Americans, I know about the Cold War.

Okay, I’ll calm down now. The “summit” everyone keeps talking about is the Washington summit of December 1987. It was the first time a Soviet leader had visited Washington since Leonid Brezhnev stopped by in 1973, and the third such meeting between Reagan and Gorbachev, after the Geneva summit of 1985, and the Reykjavik summit of 1986, both of which conveniently happened during The Americans’ inter-season time jump.

What happened in those?

In one sense, not much: The parties were unable to agree on new arms-reduction deals — though they came very close in Reykjavik — with one particular sticking point being the Strategic Defense Initiative, Reagan’s proposed system to shoot down nuclear missiles before they hit their targets. (The Soviets feared that if the SDI worked, America would be less squeamish about launching nukes unprovoked.) But even though the two sides didn’t come to any agreements in the first summits, the fact that they were sitting down and talking was, in retrospect, a major step forward, as each superpower learned that the other was prepared to negotiate in good faith.

I know about Reagan, but I’m not the world’s biggest Gorbachev expert. What’s his deal?

Let’s talk about Gorby, the man who, though he didn’t know it at the time, would be the last head of the Soviet Union. He came to power in 1985, after the three previous General Secretaries had all died in quick succession. (It’s nothing fishy, they were just old.) He was a generation younger than his predecessors, and he seemed to see the structural problems in the Soviet Union more clearly. He introduced the principles of glasnost — freeing dissidents, relaxing censorship, and allowing more public criticism of the regime — and perestroika —moving the economy toward something he called “market socialism.”

I get it, you paid attention in high school.

Wait, I’m almost done! Anyway, these reforms took on their own momentum, and Gorbachev soon found himself riding a wave that many others in the Politburo were inclined to resist. In real life, Soviet hard-liners didn’t hire the former star of Felicity to work against him, but they would’ve if they could’ve.

So, what does history tell us is going to happen at this summit?

The trust that was built up during the first two summits will pay off in Washington, where the two leaders warmed up enough to call each other by their first names. Reagan also retired his “evil empire” rhetoric for the occasion, and Gorbachev remarked later that he was encouraged by “the friendly atmosphere, even enthusiasm to some degree, with which strait-laced Washington met us.”

That sounds nice. Did they actually agree on anything?

Yes! The talks resulted in the Intermediate-Range Nuclear Forces Treaty, which called for the elimination of the short- and medium-range nuclear missiles each side had pointing at the other in Europe. The treaty was based on a plan Reagan had introduced back in 1981, and as Tony Judt writes in Postwar, it “constituted Soviet acceptance that a nuclear war in Europe was unwinnable.” Declassified documents later showed that Gorbachev had been willing to go even further, but the Reagan White House was “unwilling and unable” to match his concessions.

Why was Gorbachev so willing to concede so much?

It all comes back to glasnost and perestroika. Gorbachev was so focused on the Soviet Union’s domestic problems that, in the international sphere, he wasn’t so much concerned about getting the best deal as he was about getting any deal that would clear the table and allow him to cut down military spending. As Judt puts it, though typical Cold War logic held that any win for U.S. was a loss for the Soviets, “for Gorbachev, securing a more stable international environment was a victory in itself.”

In the show, the Soviet military is worried Gorbachev will abandon “Dead Hand” in the negotiations. Did he?

He did not. By all indications the U.S. did not learn about “Dead Hand,” also called “Perimeter,” until the fall of the Soviet Union in the early ’90s. Even some Soviets say they were in the dark about it; Gorbachev’s top nuclear negotiator told Wired in 2009 that he had had no idea the program existed. (Although he would say that, wouldn’t he.) One more fun fact: It possibly still exists!

Last question: What kind of secret spy stuff is Elizabeth going to get up to while Gorbachev’s in town?

That’s unclear, though the preview above indicates there will be a whole bunch of cloak-and-dagger-ing. However, she’ll have a lot to contend with — as the Washington Post reported at the time, Gorbachev was “the city’s most shielded visitor,” with a level of security so tight that the Soviet leader would “see less of Washington than the typical tourist from Akron.” A Secret Service spokesman called the summit “a logistical nightmare,” with more that 150 KGB agents joining thousands of U.S. agents in securing the city. Getting past all that is going to take Elizabeth Jennings’s most powerful wig.