I saw those answers, but they didn’t answer my question.
A) The first answer you sent: “The religious value of entering the covenant overrides the value of not causing suffering.”
If this were only about one-time suffering at such a young age, it really wouldn’t be much of an issue. The problem here is that you are taking from him a part of his body that you can’t give back, and this part is not marginal, because it is connected both to aesthetics and to the great pleasure that you are taking from him forever.
B) The second answer is: “There is no avoiding the influence of parents on the child’s life,” and “When he grows up, the decision to be circumcised will hurt him more and be harder for him.”
Of course I agree that parents always influence things in one direction or another, and that this always involves some gain and some loss, but the point here is the extremity. It’s different because they are harming him in a way that cannot be corrected, as opposed to diet (poor nutrition) and psychological treatment (poor education), although in extreme situations the damage caused by parents in those areas too can be “irreparable.” In the future it will indeed be harder for him to get circumcised, but at least then he will have a choice, even if it is a harder one. Seemingly, according to the logic you presented, parents can do anything they want to a child if it is “for his own good.” What would you say, for example, to certain Muslims who perform female circumcision on their daughters? That nothing can be done because parents make decisions for the child? After all, later on in the comments there below you wrote, “Everything is irreversible,” but clearly if we are talking about extreme cases then the attitude is different.
C) Regarding the third answer, I didn’t understand exactly how it relates to my question.
Thanks

To the best of my understanding, everything was answered.
A. Some reduction in sexual pleasure (when he has no knowledge of, and no acquaintance with, the fuller option at all) does not seem to me nearly as dramatic as people make it out to be. I’m not even sure there is in fact any reduction. And what does this have to do with aesthetics? These seem to me like rather strained quibbles.
B. There is not a shred of extremity here. All the other influences are far more extreme. Note that even if something is reversible (like diet), the work that must be invested in reversing it is irreversible damage.
And indeed, in my view parents may do anything within what they reasonably understand to be appropriate. I cannot judge Muslims who circumcise their daughters, because I do not know their position (to what extent this is an obligation. My understanding is that even according to them it is not, but I am not sufficiently familiar with it). As long as they are acting for the child’s benefit (as they understand it), I have no complaints against them, even if I think they are mistaken.
C. Those references are not three separate answers, but three places that discuss a similar issue.

With God’s help, sixth candle of Hanukkah 5781
The historical record shows that attempts to prohibit circumcision are דווקא characteristic of oppressive and totalitarian regimes, driven by hatred of Judaism or hatred of religion in general.
Circumcision was banned by such “liberal” regimes as that of Antiochus IV, of the Roman Hadrian, of Stalin, and of Hitler. Real liberals 🙂
Best regards, Yaron Fishel Ordner
In the United States, which really is liberal, many non-Jews also circumcise their sons because of the health benefits of circumcision.

And what if, in a liberal country, the state were to decide on the basis of research that circumcision harms the baby and therefore outlaw it—what would you think about that? Would you oppose such a law, or would you accept it?

I already wrote to you that I answered this. I would oppose it.