All human beings have the attachment system, an inherent mechanism in every human infant. This is the basic primal mechanism is designed to make us want to be in close contact with our parents. This mechanism evolved to enable us to survive and is inherent in our neurological brain.

The normal attachment mechanism is so strong that even in the case of an abusive and violent parent, in which the parent hits the child and causes harm, and there is a decision to remove the child from that parent, the child will strongly oppose.  The child blames her/himself and protects the abusive parent. 

The attachment mechanism ceases to function only for survival in cases of incest or severe physical or emotional violence, and in cases of prolonged abuse.  In the case of parental alienation, the attachment mechanism ceases to function as the child is forced to relinquish contact with a parent(s) because (s)he could not survive emotionally with the pressure exerted on her/him. The decision to sever the relationship with the beneficent parent is ostensibly the child's, but the child was led to this decision by the alienating parent. 

Ultimately, the child wants peace of mind. (S)He wants the alienating parents to leave her/him alone and not to involve her/him in the parents' world wars.
When a parent puts the child into the conflict, directs the child to total loyalty, and/or makes the child feel bad if (s)he displays affection or keeps in touch with the other parent, the child, in order to protect her/himself mentally, prefers to disconnect from the target parent to keep the peace with the alienating parent.  The child is made by the alienating parent to feel that a side must be chosen, and the target parent must be erased for peace sake. 

In the child's acute distress, the child decides to abandon the parent that he trusts and loves because there is security and unconscious knowledge that the target parent will always love receive the child back with open arms.  The child's anxiety is that if (s)he remains in contact with the target parent, (s)he will lose the alienating parent. The alienating parent will punish him/her by severing contact with the child.

The child slowly disconnects from the target parent until a total severance is made; no visits, no phone calls. The child blocks the same parent on social media and digital communication. The child does everything (s)he can to erase the target parent from his/her life.  

Here is the problem with this: the alienated child tries to look at him/herself as a “good kid”, who is doing the right thing.   This is difficult when they are simultaneously living with the memory of a good, benevolent  parent who they have coldly rejected. The child then MUST repress the good memories with the estranged parent, and mentally creates the perception of a parent who is all evil as a justification for that erasure.

The child develops delusions and a distorted reality as their mind invents an alternative, false narrative about the relationship had with the target parent in the past. The false narrative gives the justification for severing the connection: "I am doing everything a good child has to do." This is a distortion of reality is a false narrative, but the child does not feel or think that they are lying. (S)He was sure (s)he was telling the truth.  In fact, this is actually a change in the child's personality by the alienating parent.

WHAT CAN BE DONE?
Interference in situations of parental alienation can lead to a solution to the problem.  External authority that stands on its own can make a difference:  judicial decisions, sanctions, and treatment. The legal and welfare system is learning more about parental alienation today and treatment is also beginning to be more decisive. It is possible to treat the split that the child undergoes in therapy by a psychotherapist or psychologist who deals with parental alienation (an expert psychologist in the FAMILY SYSTEM THEORY) in order to mediate and restore the reality in which the child lives, and give the child the tools to cope with the alienating parent.

Treatment of the child is only one part of family therapy, which must also be utilized by the alienating parent.  If there is no cooperation on his or her part, the child will be removed in most cases, provided the target parent is equipped with the tools to renew contact with the child. However, if the welfare and legal systems are not identified, and do not support the therapeutic process, for example, by enforcing sanctions and court orders, there is little that can be done.  Parental alienation is abuse, and it develops best when it is hidden and not spoken about.  Remember, the only thing necessary for the triumph of evil is that good men do nothing.