From a Washington Post column by David Ignatius headlined “Sometimes the story is about spies who aren’t there”:

Every good spy thriller needs a “mole hunt” — a search for the foreign agent who has burrowed his way to the heart of the CIA or MI6 and is stealing secrets faster than you can say John le Carré.

The “mole hunt” trope is so familiar in fiction that it’s easy to forget that, in real life, counterintelligence investigations are incredibly destructive. They ruin the lives of innocent people and leave behind stacks of questions that might be disputed for decades.