They can.
But we shouldn't get off on a tangent about this remote possibility.

I agree with the letter writer Paul quoted above; I suspect the Qatari relatives genuinely care for the kid. They care more for his eternal soul and his being raised as a proper Muslim (in their eyes) than about any earthly-bound happiness he might have by living with his (western) mother and family.

I am sure they believe they are doing their duty as Muslims by taking him from her -- the same way most folks here think it is better to kill someone who converts from Islam than to allow them to live as an apostate.
To western ears, this sounds rather ludicrous. But to them, I am sure it seems patently obvious and clear.

"If you're looking for sympathy, you'll find it between sh*t and syphilis in the dictionary."
- David Sedaris