There's a great article about the history of circumcision and the arguments on both sides here, (also the core of it (without author's opinion) is excerpted here). It's worth noting that neither Mosaic nor Ars Technica are scholarly journals, nor is this an academic paper - rather, this is science journalism with references.
On the origins of circumcision in the West, the article says (links and emphasis added):
The best-known circumcision ritual, the Jewish ceremony of brit milah,
is also thousands of years old. It survives to this day, as do others
practised by Muslims and some African tribes. But American attitudes
to circumcision have a much more recent origin. As medical historian
David Gollaher recounts in his book Circumcision: A History of the
World’s Most Controversial Surgery, early Christian leaders abandoned
the practice, realising perhaps that their religion would be more
attractive to converts if surgery wasn’t required. Circumcision
disappeared from Christianity, and the secular Western cultures that
descended from it, for almost two thousand years.
Then came the Victorians. One day in 1870, a New York orthopaedic
surgeon named Lewis Sayre was asked to examine a five-year-old boy
suffering from paralysis of both legs. Sayre was the picture of a
Victorian gentleman: three-piece suit, bow tie, mutton chops. He was
also highly respected, a renowned physician at Bellevue Hospital, New
York’s oldest public hospital, and an early member of the American
After the boy’s sore genitals were pointed out by his nanny, Sayre
removed the foreskin. The boy recovered. Believing he was on to
something big, Sayre conducted more procedures. His reputation was
such that when he praised the benefits of circumcision – which he did
in the Transactions of the American Medical Association and elsewhere
until he died in 1900 – surgeons elsewhere followed suit. Among other
ailments, Sayre discussed patients whose foreskins were tightened and
could not retract, a condition known as phimosis. Sayre declared that
the condition caused a general state of nervous irritation, and that
circumcision was the cure.
His ideas found a receptive audience. To Victorian minds many mental
health issues originated with the sexual organs and masturbation. The
connection had its roots in a widely read 18th-century treatise
entitled Onania, or the Heinous Sin of Self-Pollution, and All Its
Frightful Consequences, in Both Sexes, Considered. With Spiritual and
Physical Advice to Those Who Have Already Injur’d Themselves By This
Abominable Practice. The anonymous author warned that masturbation
could cause epilepsy, infertility, “a wounded conscience” and other
problems. By 1765 the book was in its 80th printing.
Later puritans took a similar view. Sylvester Graham associated any
pleasure with immorality. He was a preacher, health reformer and
creator of the graham cracker. Masturbation turned one into “a
confirmed and degraded idiot”, he declared in 1834. Men and women
suffering from otherwise unlabelled psychiatric issues were diagnosed
with masturbatory insanity; treatments included clitoridectomies for
women, circumcision for men.
There's more in that vein, but it then concludes:
By the turn of the 20th century the Victorian fear of masturbation had waned, but by then circumcision become a prudent precaution, and one increasingly implemented soon after birth. A desire to prevent phimosis, STDs and cancer had turned the procedure into medical dogma. Antiseptic surgical practices had rendered it relatively safe, and anaesthesia made it painless. Once a procedure for the relatively wealthy, circumcision had become mainstream. By 1940, around 70 per cent of male babies in the United States were circumcised.
This is very much a US-focused phenomenon, though:
[W]hat’s more remarkable is that American parents are almost alone in the Western world in their desire to separate boys from their foreskins for reasons other than religion. This difference of opinion is decades old. It began in 1949, when a British paediatrician and scientist named Douglas Gairdner published the first investigation of the rationale for circumcision in English-speaking countries. He found the procedure to be unwarranted.... By 1958, the circumcision rate in the United Kingdom had fallen to close to 10 per cent. Excluding British men who are circumcised for religious reasons, the rate is now 6 per cent or lower.
The situation is much the same elsewhere in Europe. The Victorian focus on circumcision was concentrated in English-speaking countries, and its popularity never spread.
18th-century Victorian attitudes towards sex may have generated an interest in circumcision, but late-19th century medical science led to its widespread adoption in the United States. The rest of the world isn't nearly as interested.