A Baltimore-area man is caught up in a desperate fight for two young sons who he says were abducted by their Egyptian mother and grandmother last year and taken to Cairo.

Michael Shannon, 41, was awarded full custody of 5-year-old Adam and 1-year-old Jason in 2001, after he and his wife separated and she was charged with child abuse. The boys were on a court-approved, unsupervised visit with their mother last August when she took them to New York and flew them to Egypt.

Shannon hasn’t seen his children since. Nor has he made much progress in getting them back.

"It’s been a nightmare," Shannon said in a recent interview. "I haven’t been able to sleep. I am doing everything that I can legally to get them back."

International abductions of children by one of their parents are relatively common, and have become a high-profile issue among several members of Congress. But the Shannon case is unusual because it's a father, not a mother, who has been victimized.

"We lose about 1,000 children a year," said Rep. Nick Lampson, a Texas Democrat who has worked extensively on the matter and made it one of his top issues. "It is a significant problem."

Lampson said the government knows of some 10,000 confirmed cases of kidnapped American children overseas. Other estimates put the number at 30,000.

Shannon’s lawyer, Lee Elrick, said he wasn't entirely surprised Shannon's estranged wife, Nermeen Shannon, absconded with the kids.

"There was some concern initially that the mom would flee the country with the children," Elrick said. "She obviously misled him, took advantage of him. It was only supposed to be a trip to New York for the weekend, and she ran off with the children."

Elrick said he is frustrated because he can only do so much to help. "My hands are tied because the children are in a foreign country," he said. "We’re limited in what we can do here."

Shannon said his mother-in-law, Afaf Nassar Khalifa — who is wanted on international kidnapping charges in the state of Maryland — recently returned to the U.S. and was arrested and jailed in San Diego on kidnapping conspiracy charges. She was freed after posting $25,000 bail and is believed to still be in California.

Shannon is trying to get Khalifa extradited to Maryland, where the abduction took place.

Nermeen Shannon, reached by e-mail, did not respond to Fox News’ request for an interview.

Michael Shannon believes his children were kidnapped because his father-in-law, a wealthy and prominent businessman in Cairo with four daughters and four granddaughters, wanted more boys in the family.

"He wanted my sons because he needs male heirs," Shannon said.

Part of the problem in getting children back to the U.S. is that only 60 nations have signed the Hague Convention on the Civil Aspects of International Child Abduction, a treaty designed to prevent a child’s wrongful abduction. Egypt and all other Arab countries are among those that have not signed it.

"We have no good mechanism to return a child to the U.S.," Lampson said. Both he and Shannon criticized the State Department's handling of such cases.

"It is as if they are afraid to go too far, push too hard, create a problem," Lampson said. "It needs to be an agency that will fight for the rights of a citizen."

After months of pleading by Shannon, the State Department is now working on his case.

"We are trying to ensure that their welfare and safety are intact and assist in any way possible," said Kelly Shannon, a spokeswoman for the Department’s Bureau of Consular Affairs. She said the U.S. Embassy in Cairo has done several "welfare and whereabouts visits" with the two boys.

"They’re healthy and in a satisfactory living condition," she said. "We have been in regular contact with the father and we’re trying to negotiate with the mother, trying to convince her that the interest of the children is the main concern."

But she said it's not up to the State Department to determine what the best interests of the children are.

"We try to facilitate all we can for children who have been abducted abroad, within the laws of that foreign country," Kelly Shannon said. "But our laws are not enforceable beyond our borders."

That's little solace for Michael Shannon, who struggles with the guilt of what happened to his boys.

"I told Adam two years ago that nobody would ever hit him again," he said, weeping. "I broke that promise. I betrayed him. I can hear it in his voice."