When Moscow flexed its muscles and invaded Afghanistan in 1979, Soviet influence didn’t expand. Instead, the intervention spurred a coalition of resistance from mujahideen rebels, the United States, Osama bin Laden and his Arab volunteer fighters, Pakistan, and China. This turned the adventure into a costly quagmire—contributing to the collapse of the U.S.S.R. in 1991.

As the Cold War wound down, Moscow became dramatically weaker. The Soviet Union abandoned its empire in Eastern Europe. When the U.S.S.R. disintegrated, Moscow lost half its population, while nato and EU expansion brought the West directly into the Russian sphere. Today, Russia’s $1.58 trillion GDP is about the same as that of the greater New York City area, and less than one-twelfth that of the United States. Russia relies heavily on energy exports and faces falling birth rates. No wonder Putin called the collapse of the Soviet Union the “greatest geopolitical catastrophe of the century.”

Paradoxically, Russia’s waning power opened new avenues of influence. The collapse of the Soviet Union was an existential crisis for the Western alliance. In 2003, the Belgian prime minister wrote: “As long as Soviet divisions could reach the Rhine in hours, we obviously had a blood brotherhood with our cousins overseas. But now that the Cold War is over, we can express more freely our differences of opinion.” During the 2011 Libya campaign, President Barack Obama criticized allied “free riding,” and Trump has described nato as “obsolete.” Meanwhile, Russian weakness may have helped undermine the European Union and encourage Brexit. The disappearance of the Soviet Union didn’t just weaken the Western alliance—it also helped sow divisions within the United States. While factors such as globalization, automation, and immigration certainly helped increase polarization and partisanship in American politics, without a common enemy, American politics soon became even more divided.

And so, compared with the Soviet premiers of old, Putin faces a trade-off. He has a weaker hand to play, but his opponents are more quarrelsome and divided. His strategy is to make a virtue of incapacity. Direct confrontation with powerful rivals like the United States and the EU is off the table. Instead, Russia takes advantage of the divisions within the West—and within the United States—by driving wedges between its opponents, using psychological warfare, propaganda, and cyberwar.

Applying the right amount of pressure, as any veteran KGB agent would do, is an art. Moscow looks to bring just enough force to splinter its opponents, without so much aggression that it triggers a backlash. Hacking the Democratic Party’s emails in 2016 hit that sweet spot. Many Republicans concluded that “they” were hacked, not “we.” If Russia were to carry out the cyber equivalent of Pearl Harbor against U.S. institutions, it would probably unite Americans in resistance.