Left: Stephen Watkins with Alexander and Christopher. Right: Watkins and his sons Alexander, age 10, and Christopher, age seven. [Photos courtesy of Stephen Watkins]

On May 6, 2009, Stephen Watkins dropped his sons off at school, as usual. He kissed them goodbye and planned to pick them up after school on Monday, following their weekend with their mother.

That was the last time he would see them for more than two years. Alexander was 7, Christopher was 4.

The boys are now 11 and 8, and Watkins finally knows where they are - in Poland - but he cannot bring them home despite court orders, an international arrest warrant for his ex-wife, the arrest of her father for abetting child abduction and acknowledgement from Polish authorities that she kidnapped the boys.

"I didn't know where they were for two-and-a-half years," said Watkins, who said he's spent more than $250,000 of mostly borrowed money trying to have his sons returned.

Once he was informed by Polish authorities that his wife and sons had surfaced in that country - the country where his ex-wife was born - Watkins believed Alexander and Christopher would be coming home to Canada, where he was granted full custody before they disappeared.

That was not the case.

Although Poland is a signatory to the Hague Convention, an international treaty that aims to protect children from cross-border abduction, and a Polish judge decided that Edyta Ustaszewski had indeed illegally taken the children, the court ultimately found that they had been living in Poland so long it was in their best interests to remain there.

"Poland has rewarded my ex for abducting my sons," he said, the frustration and fatigue palpable in his voice.

It's a little known clause in the Hague Convention that allows authorities to decline to return children to their native country if they feel the child has acclimatized to the point they would suffer more harm by being returned, and it's one some Canadian authorities believe is being applied too liberally by countries such as Poland.

"Are there countries where it's more difficult? Yes. There are countries where they are really going to protect their citizens," said Cpl. Nadine Vaillancourt, of the RCMP's National Missing Children's Operations.

Vaillancourt couldn't speak about any specific case, but said Poland is one such example.

"It seems to be more difficult because the system that they use for the Hague Convention seems to be different from ours. There is a breakdown somewhere."

And if children are taken to countries that have not signed onto the Hague Convention at all, the best officials can do it try to mediate a voluntary return.

"In most of those cases we won't be able to bring the child or children back," Vaillancourt said.

In many countries, parental abduction is not considered a criminal matter but a custodial matter, she said, and police will not become involved.