Background
Before learning about the specifics of neonatal circumcision, you should be at least somewhat aware of the larger cultural context of the procedure in the U.S. and world.
It is an extremely common procedure done in the U.S. Current estimates suggest between 60-80% of newborn boys are circumcised, but there are wide regional and ethnic variations in incidence. It is common in Jews, Muslims, U.S. Americans, some religious Christian groups, and South Koreans.
It is distinctly uncommon in much of the world and many ethnic groups, specifically in Europeans, Asians, and Latinos. Estimated worldwide prevalence in men is about 20%.
It is a controversial procedure with debates about its potential benefits and risks and as well as the ethics of the procedure.
Pro-circumcisers emphasize the benefits of a minor and safe procedure like circumcision: decrease risk of penile cancer (U.S. data), less UTI risk, decrease risk of certain STDs, especially HIV, and eliminate risk of paraphimosis and pathologic phimosis.
Anti-circumcisers emphasize that any benefits of circumcision are not proven or largely inconsequential and do not warrant surgery with its potential risks and complications. They argue that there is no significant decrease in penile cancer risk in developed countries like Europe and Japan (proper preputial hygiene is important), that the low incidence of UTIs in boys does not justify circumcising so many for the few that may benefit, that pathologic phimosis and paraphimosis are rare and can often be handled without resorting to circumcision, that inadequate analgesia for circumcision is often still too common, that STD risk can be lowered better by altering sexual practices, and that RCT data of lower HIV risk with circumcision doesn't apply to neonatal circumcision in areas with a lower prevalence of HIV.
Others argue that neonatal circumcision is unethical genital mutilation (for boys and girls), that it can cause psychological trauma (anecdotal reports and biased surveys suggest this, but no good scientific evidence), and that it seems to lead to less sexual pleasure for men (a theoretical concern that the prepuce has some important nerve fibers that enhance sexual pleasure).