When my ex-husband and I decided to divorce, my close relationship with my son exploded almost overnight. "Luca," then six, turned into a piece of property my ex was determined to acquire. My ex did not go after our daughter, and to this day she fortunately has managed to dodge the crossfire.

Unlike most alienating parents, my ex never really wanted full custody. He wanted me to do the care-taking but let him make the decisions. His intrusiveness, combined with my son's combativeness -- he railed against me, my extended family, and my friends -- were exhausting and demoralizing.

A couple years after the divorce, I mused to a therapist my son was seeing for behavior problems that perhaps it would be better for both children if I let their dad raise them. I worried about the long-term effects of high-conflict divorce. Maybe the absence of fighting would be more valuable to my kids than the absence of their mother.

The therapist, who was aware of my ex's alienating behaviors, practically begged me not to give my ex full custody. "If Luca is having these kinds of problems spending 30% of the time with his dad, imagine what it would be like if he was with him all the time."

So I tried conventional wisdom co-parenting tactics in hopes of easing the conflict. Communicating mostly by e-mail. Setting clear boundaries. Directing my kids to speak to their dad if they complained about him instead of getting in the middle. Doing my utmost not to let my frustration over being treated like my children's au pair bleed out onto them.

I didn't realize then that conventional co-parenting strategies are useless in high-conflict divorce.

When he turned thirteen, Luca's non-compliance and explosive rages grew so intense that I felt I had no choice but to send him to live with his dad -- temporarily.

My ex, now remarried and in a position to take on more childcare responsibilities, petitioned for full custody of Luca. I had remarried as well and my husband, who had been through a six-year-long custody battle of his own, urged me to acquiesce. Given my ex's personality, his bottomless pockets, and my son's animosity towards me, my husband felt I was in a lose-lose situation.

So did my attorney. "Just give Luca's dad what he wants," he advised. "Even if you win, you can't force a teenager to see you."

Now, when faced with the imminent possibility of losing custody of my son, I felt I had to fight. Despite Luca's scorn, I knew he needed me. And there was this, the thought that kept ricocheting through my mind:

What kind of mother loses custody of her child?

The minute I shook hands with the custody evaluator, I worried I was toast. "Irv" seemed smarmy and bored and appeared distracted during our interviews. He told my husband and me how much Luca hated us and how much he loved his dad and his stepmother.

My ex is charming and supremely confident. His wife is an accommodating, don't-make-waves kind of person. My husband doesn't stand on ceremony and can be blunt. He told Irv in no uncertain terms that he didn't understand the case, that Luca had been brainwashed by his dad to hate me. Irv and my husband started arguing.

I was definitely toast now.

I consulted with a psychologist I trusted. When she heard Irv was our evaluator, she urged me to pull out of the evaluation. "I'm in a study group with him," she said. "He's lazy, he makes up his mind without interviewing collaterals, and he doesn't understand parental alienation. If his report ends up in front of your judge, it could be damaging."

So I pulled the plug on the evaluation and settled out of court with my ex-husband. I gave him full physical custody of Luca. I retained shared legal custody but in name only; my ex has sole decision-making power over Luca's education, medical, and mental health care.

Although we never went to trial, my ex told people the judge had taken away my custody because I was a mentally ill, unfit mother.

I slogged through my days, unable to sleep or eat. When I passed Luca's favorite haunts, I saw a shadow where he should have been. It was as if he had died, and a part of me had died with him.

In Gestalt therapy, there is something called the Paradoxical Theory of Change. Meaning, when you stop trying to change something, and accept it for what it is, only then can things change.

And change they did. When I gave my ex full custody, the tug-of-war stopped. Luca and his dad no longer had me to blame. They fought bitterly, Luca's behavior worsened, and my ex sent him to wilderness camp.

When I visited him there, Luca told me what he had known all along but never felt safe enough to say. His dad had been lying to him about me for years. He even convinced Luca to sign a document stating he wanted his dad to have full custody and in return promised he wouldn't send Luca away.

"He tricked me, Mom," Luca said, tears streaming down his face. "He was planning all along to send me away. I don't want him to make all the decisions for me. Can't you get custody back?"

I haven't tried, and I don't plan to. Ironically, having me "out of the picture" has enabled Luca to have a more balanced perspective. We are closer now than we have been since before the divorce. And with Luca at a therapeutic boarding school, we are finally getting the family therapy we need to repair our relationship.