A) Most countries quite rightly forbid female genital mutilation, but permit circumcision - both practices where the child has no say and is a gross violation of their bodies - why?
B) Unless for medical reasons, why do people have it done anyway?
I guess you can always say that societies can be hypocritical about so many things, male circumcision being one of the more flagrant instances. Underage female genital modification is condemned amidst howls of outrage, while underage males receive no legal protection whatsoever when it comes to the question of circumcising or not. And if circumcision is not a genital modification, then I don't know what is.
First of all, it should be remembered that aside from religious dictated circumcision (against which there is simply no logical refutation possible, it being considered a question of perceived divine will), there is only one country where circumcision is routinely customary and that is the US. There was a period in the early/mid 19th centuries when quack physicians or just plain money-grabbing quacks tout court, promoted the great masturbation scare upon parts of the public. Simply put it stated that youngsters who masturbate (boys mainly of course) were putting their mental and physical health at serious risk. Any method that could prevent masturbation was deemed acceptable. One of the proposed methods was circumcision, the reasoning going: circumcision lessen the sensitivity of the glans and less sexual pleasure will therefore dampen or ideally curb the urge to masturbate. And since circumcisions were easy and lucrative to perform, there was soon a thriving business in performing the little operation. This went over wonderfully well in households where sexuality was still a morbid issue or in hyper religious households that preached fire and brimstone and the inborn evil of humankind.
In addition to this ethical stance, the 20th century also experienced 2 world wars in which huge numbers of males were conscripted and put into military service. The military loves regimentation and rightly places great importance on hygiene. But link a perceived hygiene benefit to circumcision and you get a medical corps in the (US) military that thought that circumcision was an easy answer to many hygiene and venereal disease issues. So, in the US at any rate, military draftees were not considered properly healthy unless they were circumcised. Hence virtual mandatory circumcisions for draftees who were still intact.
This mindset was still prevalent after the end of WWII, especially since the military draft in the US continued until the 1970's.
And once Americans got into the habit of circumcising, it seemed to be a hard habit to kick. There was the 'he needs to look like his father' argument, or 'all the kids at school are cut, he shouldn't be different' or just the plain inertia of ignorance, or to put it more politely - social custom.
And now I fear, as if there aren't wars enough left to fight, there is still a great Culture War being fought out in various ways. Circumcision has also come to be identified with an old fashioned way of looking at society, with a certain forlorn longing for times past, an antipathy for change and social renewal and is one of those things that despite rational thinking, is still advocated and defended, just because it is a relic from the past.