Indeed, troubling patterns, unanswered questions, and tantalizing leads suggest that Russia relied on human sources to interfere in the 2016 election. Both the Mueller report and Intelligence Community assessments have identified a variety of Russian actors involved in the attack. They uncovered the activities of the Russian GRU, cyberhackers, and the Russian troll factory. However, one key player is missing: Russia’s premier espionage service, the SVR. Is it possible that the Russian espionage service played no role in Russia’s operation, and had no spies helping support what the Mueller report characterized as a “sweeping and systematic” attack of American institutions? The FBI would be professionally negligent if it assumed so.

Consequently, there is still much to uncover—and America’s intelligence services will work to uncover it. For example, how did the Kremlin know where to aim its disinformation effort? How did it know which communities to target, in which counties and states? One can argue that the Russians had a better sense of where to deploy their resources than did the Clinton campaign. Why did Trump and those around him consistently parrot Russian talking points? Why was the campaign so intent on disregarding expert advice on Russian issues? The Mueller report notes that while investigators couldn’t prove a conspiracy, some people nonetheless displayed conspiratorial behavior (destroying communications, engaging in a cover-up, and obstructing the work of investigators). The FBI, which has the benefit of secret intelligence, is certainly aware that it has only scratched the surface of Russian activities in 2016. Cyberhacks, troll farms, and the use of WikiLeaks are hardly cutting-edge espionage tradecraft. The Russian efforts that have been revealed to date were poorly hidden and displayed little professional elegance. Counterintelligence agencies must find it hard to believe the cupboard is already bare.