Q. My husband is on a court-ordered plan to repay child support arrears of more than $10,000. Recently, he applied for a passport, and he was denied because of these arrears. If we continue to pay as agreed, it will be years before he can leave the country. Should he, and others like him, not be given the opportunity to see the world even though he's paying as ordered?

— Marisa Duke-Potter, Columbus, Ohio

A. If parents owe more than $2,500 in back support, the State Department will reject their passport application.

It's part of the "federal commitment to help states enforce child support obligations," said Ann Barrett, deputy assistant secretary of state for Passport Services.

The help is needed: In August, 4.3 million parents owed back child support, averaging $19,300 each, Barrett said. That adds up to $83.4 billion.

That's billions of dollars that aren't going to our kids. Or, said another way, billions of tax dollars that the rest of us are having to pay because the nonpaying custodial parent will not.

So is it fair to deny a passport? Jane Rutherford, professor of law at DePaul University and the faculty director of the Schiller, DuCanto & Fleck Family Center in Chicago, said: "If you can play, you can pay."

Duke-Potter's husband, Jeffrey Potter, now rues his decision to stop paying because he longs to travel abroad. In an interview, he acknowledged he had gotten into "the typical angry thing" with his ex-spouse: They argued about visitation, and he withheld child support.

"I wish I had known that it would come to this," he said.

Potter's paying the price for what Rutherford called a "self-help solution" instead of a legal one. When a spouse withholds visitation, "the solution is to go to court," she said.

That may not be your favorite place to go, but it certainly beats not going to London or Paris or Shanghai because you want to spite your ex-spouse.

In reality, paying for kids, whether through support or in person, means you get to go to at least one interesting place — the poorhouse.

But not to worry. You'll have plenty of great traveling companions.