Then Brennan turned to an even more sensitive issue: Russia’s interference in the American election. Brennan now was aware that at least a year earlier Russian hackers had begun their cyberattack on the Democratic National Committee. We know you’re doing this, Brennan said to the Russian. He pointed out that Americans would be enraged to find out Moscow was seeking to subvert the election and that such an operation could backfire. Brennan warned Bortnikov that if Russia continued this information warfare, there would be a price to pay. He did not specify the consequences. This was the first of several...