The strongest argument for circumcision which is "Conferring belonging to a Socio-Cultural group" is also its weakest. It is weak because in todays world of enlightenment we have recognised that the highest order of human civilization is one where individual human rights are respected, and infant circumcision is a violation of these rights.
Because for many familiarity with infant male circumcision makes this concept hard to grasp at first, an analogy is required. Female Genital Mutilation is peformed to confer belonging to a socio-cultural group, yet in the west we are abhorred by the idea of female circumcision. The impact FGM has on a female horrifies us, it is done to a girl whom cannot consent, it removes healthy functional tissue & done to control her sexuality, it causes complications & acute and chronic pain, and it is a violation of her human rights! And we ask ourselves, "what sort of a barbaric society would do such a thing?" To a similar and equal degree the same can be said of infant male circumcision. An individuals' human rights to self-determination are violated by genital cutting in infancy & childhood, and therefore morally wrong. We also inadvertantly confer legitimacy to FGM if we say male circumcision is OK if it confers belonging to a socio-cultural group, yet very few in the west would want to do such a thing.
When the needs/rights of a cultural group are placed above individual human rights, terrible things can occur. At its worst, beloging to a socio-cultural group can be used to exclude others and in extreme cases murder and genocide occur when belonging to a socio-cultural group becomes more important than the individual human rights of those who belong outside that socio-cultural group.
We need to be very careful when we selectively put the interests of the socio-cultural group ahead of individual human rights, because Infant circumcision done to confer belonging to a socio-cultural group is a violation of the human rights of that individual!!!!!!