Back in 2016, the Kremlin had a golden opportunity. Faced with a choice between Hillary Clinton, a Russia hawk whom they loathed, and a gullible businessman who was new to politics and completely enamored of Vladimir Putin, they picked the latter. Evgeny Prigozhin’s troll farm, the Internet Research Agency, swung into action, creating fake social media accounts and stories and buying ads on Facebook. More importantly, the Russian security agencies, the G.R.U. and F.S.B., hacked the D.N.C. and Clinton campaign chief John Podesta’s emails and leaked the information at maximally damaging moments (right before the Democratic convention and just ahead of the election, respectively). The result was chaos within the Democratic Party, an electorate that swung just enough toward Donald Trump for it to count, and the scandal that became known as Russiagate.