Definition
Isolation is the gradual separation of a person from competing influences — friends, family, routines, advisors, anyone who would offer an independent perspective. Greene describes seducers drawing a target into a private world, an exclusive "us" where the seducer becomes the dominant or sole reference point.
What feels like intensity — "I only want to be with you" — is also a structural change. As outside voices recede, the target loses the external checks that would let them evaluate the relationship clearly.
Why it matters
How it works
Isolation rarely announces itself. It accumulates through small steps: subtle criticism of friends, scheduling that crowds out other relationships, framing outside ties as disloyalty, and the seductive flattery of an exclusive bond. Each step is individually deniable, but the cumulative effect is a person whose entire informational world runs through one other person. Without outside references, the target cannot tell whether the relationship is healthy, and the controlling person becomes the sole authority on reality. The defense is straightforward and worth defending actively: keep your friendships, your routines, and your independent counsel intact.