She had raised her daughter for six years after a divorce. Then Lt. Eva Crouch was mobilized with the Kentucky National Guard, and Sara went to stay with Dad.

A year and a half later, her assignment up, Crouch phoned her former husband to say she would pick up the child the next day.

"Not without a court order you won't," he said.

Within a month, a judge would decide that Sara should stay with her father. It was, he said, in "the best interests of the child."

What happened? It's a question Crouch and other parents who are called to active duty are asking. Crouch was the legal residential caretaker; this was supposed to be only temporary. What had changed? Her only misstep, it seems, was answering the call to serve her country.

Crouch and an unknown number of others among the 140,000-plus single parents in uniform fight a war on two fronts: For the nation they are sworn to defend, and for the children they are losing because of that duty.

A federal law called the Servicemembers Civil Relief Act is meant to protect them by staying civil court actions and administrative proceedings during military activation. They can't be evicted. Creditors can't seize their property. Civilian health benefits, if suspended during deployment, must be reinstated.

And yet service members' children can be - and are being - taken from them after they are deployed.

Some family court judges say that determining what is best for a child in a custody case is simply not comparable to deciding civil property disputes and the like; they have ruled that family law trumps the federal law protecting service members.

Even some supporters of the federal law say it should be changed - that soldiers should be assured that they can regain custody of children.

In 1943, during World War II, the U.S. Supreme Court held that the soldiers' relief law should be "liberally construed to protect those who have been obliged to drop their own affairs to take up the burdens of the nation."

Shielding troops allows them "to devote their entire energy" to the nation's defense, the law itself states.

But child-custody cases are different.

Dale Koch, president of the National Council of Juvenile and Family Court Judges, said that as state court judges, those deciding custody cases are obligated to follow their family codes - and "in most states there is language that says the primary interest is the best interest of the child."

"You don't want to penalize a parent because they've served their country," said Koch, an Oregon judge. "On the other hand . . . you don't want to penalize the child."

But what does "best interest" mean?

Koch mentions factors such as stability and considering who has been the child's main emotional provider, parameters that conflict directly with military service.

Iowa Guardsman Mike Grantham thought he was serving the best interests of his children when he arranged for his son and daughter to stay with his mother before reporting for duty in 2002. He had raised them since his 2000 divorce, when his former wife, Tammara, turned physical custody over to him.

After mobilizing, Grantham was served with a custody petition from Tammara. A trial judge temporarily placed the children with her. A year later, though Grantham had returned, the judge made Tammara the primary physical custodian.

An appeals court sided with Grantham, saying: "A soldier, who answered our Nation's call to defend, lost physical care of his children . . . offending our intrinsic sense of right and wrong."

But the Iowa Supreme Court disagreed, saying Tammara was "presently the most effective parent."

Now, Grantham said, his visitation rights mirror those that his former wife once had: every other weekend, Wednesdays, and certain holidays - Father's Day, for example.

"Being deployed, you lose your armor," he said.

Military and family-law experts don't know how big the problem is, but 5.4 percent of active-duty service members - more than 74,000 - are single parents, the Department of Defense reports. More than 68,000 National Guard and reserve members also are single parents. Divorce among service personnel is rising.

When Crouch was mobilized in 2003, her former husband, Charles, wanted 9-year-old Sara with him. They moved Sara's belongings, and Crouch headed out.

But when the time came for Sara to return to her mother, Charles said his daughter expressed a desire to stay with him. She liked her school and had made new friends.

"I had no intention of trying to talk her into staying or anything," he said. "All I wanted was what was best for my daughter."

Last year, the state Supreme Court cited a new Kentucky law, requiring that temporary custody and visitation changes made because of military deployment revert back to the original agreement once deployment ends, in overturning the trial judge's decision granting custody to Charles.

Last September, Eva Crouch got Sara back.

Remarried now, Crouch is expecting a baby this August. But with 18 years in the military, she knows she could be mobilized again. One thing is clear to her now: Serving her country isn't worth losing her daughter.

"I can't leave my child again."