What you mean by saying that most men on the US are mutilated at birth? i never heard of that, i curious are you referring to jews? aren't they a minority?
Circumcision. It is a general mutilation with the purpose of destroying sexual pleasure, even more because the sexual anatomy of man it's very different to woman.
Now i will explain why.
The human penis was made by an evolution of our intelligence, social endeavors and sexuality based bonding (monogamous normally), females are very sexual in our species, the clitoris is a full structure with the purpose of reducing incontinence, having more support on the vagina (including with this the act of childbirth), making the distinct shape of it and to generate all of the sexual pleasure in the female
This made women very picky, because as a social species, orgasms where made more important as a bonding mechanism, so they started picking men based on how their dick functioned, this made the foreskin more advanced, so they could do small movements inside the vaginal canal, so they could pleasure all the parts of the clitoris, while at the same time having an ejaculatory moment where they could end the act rapidly (normally if they were predators on the area).
Men evolved with this too, making the foreskin the most sensitive spot (Men have 8,000 of them on the foreskin, which is the exact same quantity as women on their clitoris, in general we have 8,000 nerves on our most sensitive parts while we have 4,000 on everything else, this includes women too), only activated by light touch by Meissner's corpuscles, which only generate pleasure with slow moving motions, thus generating the real masculine orgasm by the virtue of the light touch.
The foreskin is more like the female clitoris, they work together and have a lot of function, like protection, a ridged feeling, immune response. a general double swiping motion and more (the clitoris has a lot of functions too), in general FGM and MGM are extreme ways to control other people and their lives, which normally causes traumatized people who cannot develop correctly, this most likely generates a lot of aggressive behaviors most ideologies of the US or middle east have.
This even explains why women normally want their men to moan, but can't seem to manage it, they don't know about the purpose of the foreskin, just like women in the past didn't know about the use of the clit.
Men have alien penises which move and are the main pleasure point, women have a big creature beneath their skin which aids on everything