One compelling storyline in the Oscar-nominated film “Marriage Story” reveals how two people who still care for one another, and who adore their young son, end up in a bitter and costly divorce.

The Hollywood portrayal of a drawn-out, painful and expensive custody battle is hitting close to home for those in the trenches of relationship warfare. Katy Walter, chief executive officer for Kids In the Middle, a nonprofit organization that helps families during and after divorce, says they are seeing an increase in the number of high-conflict family transitions. Several divorce attorneys report the same trend.

“I think they’ve become more contentious,” said Joseph Lambson, a divorce attorney based in Clayton, Missouri. “It seems like divorces are falling on one of two paths,” he said. “Either they mutually realize it’s in their best interest to keep it focused on the best interests of the kids, or it’s a full-throttled attempt to gain the upper hand.”

So, why are custody battles getting messier?

Lambson said there’s a noticeable rise in the number of cases involving a mental health diagnosis for one or both parents, or one of their children.

“I have seen more cases in 2019 than the previous five years combined” that involve mental illness, he said. That puts one parent into the role of trying to protect the child from the other parent, or it can spar disagreements on how to handle a child’s special needs.

Attorney Susan Block, also of Clayton, agrees that mental health disorders are playing a bigger role in divorce proceedings, as are substance abuse issues. Sadly, the mental health of the children sometimes takes a back seat to the desire of sparring parents.

“Right now, we are seeing a lot of anxiety, isolation, social media being abused,” she said. The move toward shared custody may not be the best solution for children in this situation.

“A kid that is anxious cannot benefit from that many transitions,” she said, especially if there are different rules and routines in each household. Lambson agreed that the trend toward 50/50 custody has not reduced litigation in Missouri.

“There’s more to fight about,” he said.

Unique parenting plans can create more conflict among parents who already aren’t communicating well, Walter said. And when a plan breaks down or needs to be modified, the family ends up back in court. She said they are also dealing with more cases involving parents who have never been married, which can complicate co-parenting arrangements.

She added that many of the same tensions and problems present in society filter down to families. For example, if a parent airs his or her grievances on social media, a child could access that.

“When kids come in, the amount of information that they know (during a divorce) is pretty astounding,” she said. Most of this information isn’t helpful for the child.

Susan Myres, president of the American Academy of Matrimonial Lawyers, said the rise in contention in divorce is mirroring the rise in conflict in society.

“There’s high conflict because bad behavior is not punished,” she said. “You can say and tweet all sorts of offensive things, which triggers an offensive response, and there doesn’t seem to be accountability.”

She suggested that if there were serious consequences for a person tweeting insults and mistruths, repeating bad things to children, or yelling at others during a divorce or separation, then these behaviors wouldn’t be as prevalent.

Today’s polarized environment can also make co-parenting more challenging for those on opposite sides of the political divide.

Jason Young, 49, of Chesterfield, Missouri, divorced nearly 11 years ago when his children were young. He and ex-wife Cynthia O’Toole, 43, of O’Fallon, Missouri, have vastly different political views.

Young said it has created some moments of tension -- for example, when his young daughter comes to his house wearing the T-shirt of a candidate his mother supports and he strongly opposes. Meanwhile, O’Toole says she is disturbed when her children come home “with a crazy idea or crazy view” they’ve heard from their father.

“That poses a challenge,” she said. “I basically bring them back to reality.”

Despite their differences, both Young and O’Toole say they had a relatively low-conflict divorce.

“I learned a long time ago that fighting doesn’t solve anything,” Young said. During their separation, they kept the best interests of their kids front and center.

That, experts say, is the key to avoiding additional heartache.

I dropped the handwritten thank-you card into my “good mail” folder in the file cabinet under my desk. That’s where I keep a few of the best notes mailed from readers.

I had no idea Ria Van Ryn had been dying of cancer when she sent it. Maybe she didn’t even know herself.

I first heard of Ria when she taught my daughter’s English class in ninth grade. My daughter mentioned that “Dr. Van Ryn” was a tough but excellent teacher.

Someone with a doctorate, teaching freshman English in a public school? That’s a little unusual.

It turns out that Ria often chose the unusual path. She had just left a tenure-track teaching position at Yeshiva University in New York City -- a position she earned after getting one master’s degree in religious studies, as well as another master’s and a doctorate in sociology.

But it was too expensive to live in Manhattan on a young academic’s salary, and she had a dream of becoming a mother.

So she headed back to St. Louis, where she had been raised, and where her mother and one of her sisters taught in her childhood school district. She earned her third master’s degree -- this one in education -- and a teaching certificate before getting a job teaching high school English and social studies.

Raised Unitarian, Ria had converted to Judaism in graduate school.

Her dissertation focused on a Jewish day school and a Muslim day school: She was interested in how children followed their parents’ religious traditions and how they learned about other religions. At the end of her project, she brought the kids together for a day of service and a shared meal.

As devoted as she was to her students, she wanted a child of her own. She was single, and decided to pursue fertility treatments. It took a year to get pregnant.

She gave birth to Schuyler in August of 2017, when she was 37.

Her family was thrilled.

“She was Jewish by choice and a single mother by choice,” her sister Trina Van Ryn said.

Ria told her parents, Debbie and Jack, that they were going to be co-parents with her. A tight-knit family, they call themselves Team Van Ryn.

In July of 2018, when Ria’s eyelid started drooping, her father urged her to have it checked out. A CT scan showed she had gastrointestinal neuroendocrine cancer with tumors in her chest and stomach: a rare, aggressive and unpredictable cancer.

Her daughter was 11 months old.

Ria didn’t want to know the survivability rate; whatever it was, she had every intention of beating it. She had been a state-level swimmer in high school, and had run 13 marathons. She would fight this.

Her father, an orthopedic surgeon, knew the odds.

The family kept their fears and grief to themselves. They were Team Ria.

“We will be with you every step of the way,” her sister Zannah told her.

Ria filled a binder with information and questions, and carried it with her to every doctor’s appointment. She went through seven different chemo and immunotherapies in 15 months.

She also kept teaching.

During this time, she emailed me -- “at no small risk” to herself, she wrote -- to talk about incidents of racism in the school that concerned her. Eventually, she took her concerns higher, personally meeting with the district superintendent.

“What do I have to lose?” she told her mom. “I have cancer.”

Her family rarely saw her cry -- only when she talked about wanting more time with Schuyler.

But she never talked about dying.

Shortly after Christmas, my daughter’s principal emailed the students and parents about Ria’s death. When I read her obituary, I realized we had both graduated from Trinity University and majored in sociology. She had taught my daughter, and yet we had spoken just once, about a story tip.

Ria’s Unitarian family sat shiva for her.

On New Year’s Day, three days after her death, Schuyler asked her Grammie and Opa, “Where’s Mama?” She knew her mother had been in the hospital and sick, but she wanted her now.

Both of them took her by the hand and walked outside.

“See the sky, where it’s so blue?” Jack said, pointing up. “That’s called heaven. That’s where Mama is, and there are no boo-boos in heaven. Mama’s going to stay in heaven, but she wants you to stay here with Grammie and Opa.”

Two-year-old Schuyler looked up to the sky and said, “Hi, Mama.”

She turned to her Opa and said, “Mama blew me a kiss.”

I wish I had written back to Ria when she sent me that note a few months before she died. I think about the writer and reader my daughter has become. Ria helped do that.

Through the lives she touched, she’s blowing kisses back to all of us.

Earlier this week, my 14-year-old son asked a startling question: Do you think there’s really going to be World War III?

Like most kids with a smartphone and access to social media, he had seen the chatter about war spiking after President Donald Trump ordered an airstrike that killed Iranian Gen. Qassem Soleimani in Iraq. From mushroom-cloud memes on Twitter to TikToks about dodging a possible draft, teens processed their anxiety, ironically, on anxiety-provoking social platforms.

World War III hashtags started trending again when Iran retaliated by firing missiles at Iraqi air bases housing U.S. forces.

Gen Z found a way to mock the fears that gripped most informed adults about the potential for escalation in the conflict with Iran. It makes sense, given the outsize role violence has played in their childhood. War is both near and far in their imagination: They’ve grown up in an era of never-ending war, in which America is time and again dropping bombs on some far-off country. Meanwhile, their schools are regular settings for the mass murders of their peers, to which our leaders respond by having children role-play being stalked and killed by a mass shooter. Children can watch animated videos on YouTube about what would happen in a nuclear war.

How do we expect them to cope? They see adults unwilling to protect them from the existential threats facing their generation -- from gun violence to environmental catastrophe -- and willing to excuse and protect certain evil regimes in which they have a vested economic interest.

The kids aren’t stupid.

The notion of a third world war, in particular, is tied to fears of a nuclear war and annihilation. Those of us who grew up during the Cold War understood those theoretical risks, but we didn’t face those apocalyptic ideas bombarding us when we simply wanted to talk to our friends. Or watch a video. Or play a game.

When the prospect of war looms, my thoughts go to the people I know who would be most directly affected. As soon as I saw the news of the strikes on Iraqi air bases, I texted our close friends whose son is an officer in the Air Force and just returned last month from Iraq. He had been stationed at one of the bases attacked.

“Just pray he doesn’t have to go back,” my friend said.

I opened Facebook and saw another friend had posted a prayer request for her niece, stationed at one of the targeted bases, taking shelter in a bunker.

I think about the funerals I covered of young American soldiers from the U.S. invasion of Iraq in 2003. While no one knows exactly how many innocent people have been killed and wounded in Iraq since that invasion, the Watson Institute for International and Public Affairs at Brown University reports that more than 182,000 Iraqi civilians died from direct war-related violence. Civilians. Brown’s Costs of War report found that the U.S. “War on Terror” has cost the U.S. $6.4 trillion and led to the deaths of 335,000 civilians worldwide. That’s more than the total number of deaths in Hiroshima and Nagaski combined. In the case of Iraq, the argument about “weapons of mass destruction” given to the American people to justify the war turned out to be false.

Maybe that’s why the dark humor war memes seemed chilling to me. We know that the things we want to believe could never happen are entirely possible.

To answer my son’s question, my impulse was to be as reassuring as possible.

“No, I don’t believe World War III is going to happen,” I told him.

To myself, I said a prayer.