Supremacist?
Jesus wept.
Do you feel the same way about casually cutting off a baby's little toe, or a bit of their ear, or taking a chunk of flesh out of their back at birth for no medical reason? It's really unlikely to have any serious consequences for their life so maybe the parents should be allowed to do it if they believe that God told them to? Or just because their parents did it to them etc.? Or just because they enjoy it? I mean, why does the motive really matter?
Then we don't have to bother lifting a finger to protect those "other" children being mutilated (while continuing to prosecute anyone who does the same to our own children) and, as a Brucey Bonus, we can pat ourselves on the back for our wonderful and tolerant open-mindedness.
I mean, there are well-documented accounts of tribes routinely practicing CSA as part of their culture too. Is it OK for that to continue being done to 'those' kids too (particularly on our shores) so that we don't overstep into colonial supremacy?
If you think that child genital mutilation is, as you say, "cruel", why are you more afraid of being seen to be "supremacist" than preventing cruelty to children?
Where exactly do you draw the line with the moral relativism and on what basis?
Obviously no need to answer if you don't want to - you certainly don't owe me any explanations! But interesting to ponder to yourself who has primed you to be so reticent about calling out things that you clearly feel are truly and seriously wrong and to what end.
Incidentally, and to be very clear in case people draw adverse conclusions - I have a high respect for Judaism on many respects and this is not an opinion I hold because of who is traditionally associated with its practice (the USA seems to have an extremely odd approach to this in general, too, for example).