s Trump won primary after primary in 2016, a rattled John Brennan started claiming to colleagues at the CIA that Estonia’s intelligence agency had alerted him to an intercepted phone call suggesting Putin was pouring money into the Trump campaign. The tip was bogus, but Brennan bit on it with opportunistic relish. Out of Brennan’s alarmist chatter about the bogus tip came an extraordinary leak to the BBC: that Brennan had used it, along with later half-baked tips from British intelligence, as the justification to form a multi-agency spy operation (given the Orwellian designation of an “inter-agency taskforce”) on the...