Is attendance at secular school a necessity where it is the law of the country, yet impressionable children's Imaan is most definitely at stake?

Answer

If there is a real danger of the parents being arrested for not sending their children to secular school, then Hijrat (Migration) becomes Waajib. If for some reason this is not possible, and if being arrested by the kuffaar authorities is a real danger, and if home-schooling is not allowed, and there is no escape route then they may comply with the haraam law of the kuffaar. However, as long as the option of home-schooling is available, it will not be permissible to send the children to public schools, even to these so-called 'islamic' schools. In fact, the lesser of the evils between kuffaar secular schools and these shaitaani 'islamic' schools, is the former.