Your brother in law is right unless they get at least phone permission they will not treat your son unless there is a threat to life or limb. At best his treatment would be delayed without the letter. It's an easy thing to do so why not?
YOUR son is wrong, I am the grand parent and the docs had to have direct permission from the mother so that the baby could be treated............your brother is right send the letter with EXPRESS dates stated on the letter, with the proviso that you are to be called regardless of the TIME........after all unless you give the letter there is a high chance the other parents will be slow to take your son. Any time your child is under 18 and you are not there it becomes an issue and until your son is grown and has sat in an ER with FULL insurance with a child that needed stitches and she sat in a puddle of her own blood while they sorted out paperwork which took over 6 hours I suggest he hushes................. we went through that bs and it was my child and we have all singing all dancing insurance.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.