Basic coercion refers to the situation where the survivor, to have any peace or stability in the relationship, must give in and comply with what the primary aggressor wants. The survivor understands that the situation will escalate or remain tense until they give in. Unsolvable conflict and disruption is used by the primary aggressor as a punishment when the survivor does not do what he wants. Casual observers who do not see evidence of battering may well miss the coercion actually present.
The expression "My way or the highway!" touches on basic coercion, but in most abusive relationships, 'the highway' is a bluff and leaving is not really allowed. Basic coercion is easily distinguishable from setting boundaries. There are two aspects of basic coercion worth discussing a bit further: pressure release, and threatening to leave.
Pressure-Release as a Tactic
A basic illustration of pressure-release as a psychological control tactic is the well-known theme of good cop/bad cop. Any human person habituates physically a bit to any sustained pressure or discomfort. If the pressure or discomfort is removed suddenly, there is a physical rebound of relief feelings. If there is an identifiable person responsible for the relief, or even a person in the vicinity, gratitude is usually felt toward that person.
In a situation of domestic violence, primary aggressors often act out mood swings. That is, intensely coercive behavior may be replaced suddenly by civil behavior or modestly rewarding behavior. This produces a physiological experience of gratitude in the survivor. Survivors lose their internal compass, and periods of mere civil behavior come to be regarded as 'good' periods, partly just by contrast, but also through the mechanism of relief feelings.
Control is ever present, however. Primary aggressors will use the relief feelings in the survivor to exact more compliance.
Threatening to Leave a Relationship
Leaving a relationship should always be an option if boundaries are violated or satisfaction is absent. Relationships should not work as a trap that limits options.
Frequently though, when one partner's legitimate expression triggers the shame or rage of the other, the triggered partner can not imagine accepting the 'change' in the other partner, and so a threat to leave is reflexively thrown back. The threatening partner does not mean to leave though, because the shame binds him all the more dependently in the relationship. Threats to leave really block communication and cooperation, however.
Shame-based threats to leave are not actions that protect integrity. Not getting one's way is not a boundary issue. Not liking what one is hearing is not a boundary issue.
Primary aggressors learn quickly that threats to leave can be used for power. Threats to leave shift the focus from the primary aggressor's behavior to the survivors’ behavior, which is the fundamental abusive maneuver (deflection). Usually, threats to leave are produced when accountability is asked for.
In a respectful relationship, room is allowed for partners to bring complaints and hold up a mirror to a side that the other partner doesn’t see or doesn't want to see. This requires a certain stability. If a man threatens to leave whenever the heat gets too hot, it is attempt to silence the partner. Threats to leave can act like a trump card that renders the original conflict irrelevant.
Because women take strong interest in a relationship working, they are often strongly affected by threats to leave. Many men have learned this and exploit it. Like all power behaviors, threats to leave are subject to rapid and dangerous escalation if they do not have the intended effect. Many physical assaults are committed by men who, ironically, had moments before said they were done with the relationship.