Would you do the following..

I would not give the younger child this kind of control over the older one. The kid can't refuse to have the surgery.

Book the elder one in for a lobotomy and ask the youngest if they think the rule still applies.

Even hypothetically, this is a bit way out there. Of course, EVERYONE is afraid to have surgery, especially children. The fear is pretty simple: "I am going to be cut open!" A physician would never do an unnecessary medical procedure on anyone (regardless of the non-ethical desire), nor recommend canceling the surgery due to fear.

It's not up to the parents to decide who has surgery, so thats not even an option. I would talk to the child about The fears, maybe visit the hosp before surgery. Some hospitals will give a young child a tour of the pre-op room and the recovery room and explain everything that is going to happen.

Talk to the child, but ultimately if the one needs it and the other doesn't, then only the one would get it. I would not put another child through unnecessary surgery for the sake of the younger.

Other. Handcuff my dumbass kid while s/he's sleeping, duck tape him/her so they can't move, and drive their ass to the hospital.

Talk to the kid and explain to them why they need to have tonsillectomy. Try not to use big medical words but explain in plain terms the importance of the procedure.

Also, bribe the kid with ice cream. That's what my parents did to me - I was quite a happy 6 yo going into surgery.

Seriously?

If the surgery is needed, it's not the kid's choice.

If it were my child, the surgery would be presented to her as something that is necessary. She would not be given the choice, but I would be very supportive and stay with her every step of the way.

When my daughter was afraid of the cast saw, I didn't let her just leave it on.

Of course I'd talk the kid about why they were afraid, but if the kid needs the surgery, they get the surgery. For sure the older kid does not get unnecessary surgery just to placate the younger.

The child has no choice. BUT, I would not allow my child to have a tonsillectomy. The tonsils are a part of the immune system. If I only knew many years ago, what I know now, I wouldn't have allowed my son and daughter to have such procedures.

Explain to the younger child that this is non-negotiable and they will die a horrible horrible death unless they do what I say right now.

Tell the younger one to grow up, he's getting the surgery, and there is nothing he can say or do about it.

Make the child go through with it. Who is the parent here? Children obey, not have a choice.

The child has no say. The parent or legal guardian makes all medical decisions until a child is of legal age or emancipates itself.

Even if you, as the parent were stupid enough to ask to have a child's tonsils removed to pacify their sibling, I would hope that no surgeon would actually be willing to do it for that reason.

I'm assuming that these are very young children. I would talk to the younger one and try to explain why he needs the surgery and try to understand his fears. Ultimately though, if there is a clear clinical need (bearing in mind that tonsils aren't whipped out at the first sign of trouble any more), he's having the operation - if he's young enough to make such a childish demand, he isn't old enough to refuse to consent to a surgery. I'm not able to imagine a situation in which, with a bit of time, I wouldn't be able to reassure my own small child.

Uh... who is the parent here? Any child of mine would know that "refusing" wouldn't get them more than a laugh from me.

Oh brother.

Either a kid needs a tonsilectomy or they don't. It's not negotiable.

I'm sure to talk to the kid about their fears, but that talk would include dispelling any myth that siblings or anyone else have similar circumstances or requirements.

Talk to the younger and try to reassure them about the surgery.

find out the fear. Other than surgery has it's awful risks...the long term effect of living without tonsils...and the tonsils as being only part symptom of what is really out of balance with the body and removing an organ is only removing a part of the body that is doing it;s job.

Oh, those are my fears.
I would discuss the fears, and explain how selfish it is to expect the other child to suffer for someone else's own journey.

Talk to the younger kid. The kid wouldn't be allowed to "refuse" something like this.

The kid that needs the surgery gets the surgery and the one who doesn't, well, doesn't. We are talking about a minor here right? Since when does a child not only get to decide whats good for him/her but also make a huge decision about a siblings life?