Is it fair that because the courts in the United States will not enforce a child custody order from Saudi Arabia?

Is it fair that because the courts in the United States will not enforce a child custody order from Saudi Arabia because it violates our public policy, children born there to an American mother and Saudi Arabia father are not allowed to visit the United States before age 18? This is because it would be a criminal offense under US law for him to take the same children back to Saudi Arabia.