‘Absolutely, breastfeeding is best for babies and for mothers,” says Gill Walton, chief executive of the Royal College of Midwives. We were talking yesterday, just after news broke of a major development in the territory of infant feeding. “But anybody supporting women needs to give them support to bottle feed safely, if that’s what they decide to do.”

This support for mothers who bottle feed has been hailed as the end of a battle that has raged for at least a decade, the Treaty of Versailles in a postpartum wrangle in which the breastfeeding side was considered so righteous that it didn’t even have to acknowledge the other one.

Walton’s position sounds so straightforward, so obvious: why would you ever not want to support bottle or mixed feeding women, given that they represent over 60% of the population? Yet the orthodoxy that breast is best had become so established that the answer to those women for whom breast was, in fact, worst, was always: you need more support.

It would take a woman with first-hand experience of painful or ungenerative milk production to really give voice to how undermining and unjust this “support” mantra was, but I’ve heard it done – so have you, probably – and they use some pretty fruity language. It really isn’t the case that all women can breastfeed perfectly well, if only they have enough health visitors. Clare Byam-Cook, a nurse and midwife turned guru, is the Madonna of old-school breastfeeding experts, and she always had this as a backstop: if it’s really not working, stop doing it.

But since the start of this century, pragmatists have been increasingly drowned out in favour of a 00s absolutism that affected all kinds of areas of parenting (principally, motherhood): a mother who would accept second-best was barely even a mother. Breastfeeding was the frontier issue in a burgeoning culture where intense risk aversion was a sign of perfect parenting. It covered alcohol in pregnancy, soft cheese, stress; at one point, the Royal College of Obstetricians and Gynaecologists put out advice to pregnant women not to sit on new furniture. Breastfeeding was its purest iteration, partly because everyone could see it and judge it; partly because it was a chance to legitimately instruct women to subsume themselves utterly to their child’s welfare; and partly because the science was apparently so settled. Breastfed babies were less likely to get gastroenteritis, less likely to get ear infections and eczema, less likely to become obese, both mothers and babies were less likely to get cancer, and they would have a higher IQ (typically, the uptick was six points, with some wild studies claiming far more). Advice from the Department of Health, spinning out from that of the World Health Organization (WHO), was to breastfeed exclusively for the first six months, or, to put that in baby language for the new mum: “Don’t rush to mush”.

The problem, in the first instance, was that, for all the certainty with which it was discussed, the science was never actually that settled. A lot of the WHO evidence was taken from studies of women where a clean water supply wasn’t assured, or they couldn’t necessarily afford adequate formula. Bottle feeding was always, therefore, going to be difficult, if not impossible. Comically, one of the reasons that was given in favour of breastfeeding was that it prevented the return of menstruation, and therefore acted as a contraceptive This is comical, a) because it’s not very reliable and you actually can get pregnant while you’re breastfeeding, and b) because a woman in Keswick does not need to breastfeed in order to prevent a pregnancy. It’s like telling a population in South Korea to clean a wound with ash to ward off infection: ash might be better than no ash, but not if you’ve got Germolene.

The gastric effect was pretty well established (although the much-quoted interventionist study in Dundee was extremely small), and its mechanism known and understood – it hinges on a specific agent found only in human milk, secretory immunoglobulin, or SIgA. Critically, though, as the American academic Joan B Wolf, author of Is Breast Best?, summarised: “The majority of studies have demonstrated that there’s a relationship between breastfeeding and better health. But whether this relationship is causal has never been established.” No study has ever been able to disaggregate the act of breastfeeding from the decision to breastfeed – which is to say, the milk itself from the kind of mother who chooses to feed her child breastmilk. So it would be unwise to discount the possibility that what we were seeing was not the magic properties of “liquid gold” (as my midwife used to call it) but the health benefits of being born into one social environment over another.

The fury, if you ever pointed this out, was truly bizarre, and it is for this reason, I think, that the RCM and many other bodies have until now steered carefully along a course almost entirely dominated by the breastfeeding enthusiasts (or lactivists, if you prefer). Writing anything about evidence bases, much like writing anything about economics, always invites a fair amount of sneering (“Why, oh why, does this journalist think she could ever understand this material which only I understand”) but this is, funnily enough, the only time I have ever been physically threatened: I covered some of that evidential insufficiency – which is explicitly accepted by the American Academy of Paediatrics – and shortly afterwards chaired an event for the RCM. The then chief executive, who was actually brilliant, although we disagreed about breastfeeding, warned me that some people were intending to protest, and maybe throw things. What kind of things? Oh, nothing serious. Maybe an egg. On the one hand, I was actually breastfeeding at the time, so was always covered in stuff. But on the other, I had just had a baby. I really didn’t want anyone throwing eggs at me.

Spleen tends to attach to cases that are not as strong as they claim. The underlying issue was class-based: breastfeeding, the middle-class choice, gave middle-class parenting a superior status that would otherwise have been difficult to assert. In fact, during this period, the non-middle-class parent was under constant and strange attack: when the coalition government came in, the First Three Years became a key policy area, with improbable and unpleasant assertions about what non-U parents were like. They fed their babies formula, then they left them all day strapped into a buggy, pointed at a wall; they didn’t give them the right vocabulary because they weren’t interested in talking to them. Bottles became a key signifier of parental neglect, and I always wondered why the women who couldn’t breastfeed didn’t kick up more of a fuss about this, since the alternative was to bottle feed your baby with a sense of shame. But parenting is a great leveller, and some people don’t want to be level.

The Centre for Parenting Culture Studies, at Kent University, did fascinating work on this and many of those other trigger issues, culminating in Charlotte Faircloth’s PhD thesis, Full-term breastfeeding: Nature, morality and feminism in London and Paris: “Everything had become very heated, moralised. How you feed your kids is no longer a personal decision. There’s this idea that you can breastfeed your way out of poverty. It all got a bit out of hand.”

There were dissenting voices, interestingly from French rather than Anglo-Saxon feminism: Élisabeth Badinter caused an incredibly strange controversy in the early 2010s, when she said: “If, 24 hours a day, the women is reduced to her role as a nursing animal, the father is completely put aside.” This was a red rag to the feminism that says women should be making their own decisions when they become mothers, and shouldn’t be worrying about what their partners think: but in fact, a women’s rights framing – in which the woman is “liberated” from her sexual identity, in order to be ruthlessly policed in her maternal one – isn’t very feminist either. At its simplest, Badinter’s message was: “There are women for whom breastfeeding is a true pleasure. It’s very good for them and very good for the baby. But to breastfeed a baby if the mother herself doesn’t like it? It’s a catastrophe. The decision to breastfeed is an intimate and private decision. No one should be able to interfere.”

And that is where the RCM has also landed. “It’s part of a wider campaign we’ve got about trusting women,” Walton explains. “There has been an increase in mental health problems following childbirth, and while we can’t ascribe that to the previous breastfeeding advice, we do know that there are lots of women feeling guilty, made to feel guilty by their friends and their families. We’re saying, once they’ve made their choice, trust them. Actually, what you need to get right is to feed your baby and love it.”

This has been a culture war, and quite an exhausting one, where nothing meant exactly what it said: the pro-breastfeeding line originated with second-wave feminism, asserting a woman’s choice to feed with her baby as she saw fit, without medical or corporate interference. That liberation became an oppression; if it’s the only thing you’re allowed to choose, that’s not a choice. It fed into a set of ideas that located the source of childhood disadvantage not in hardship but in their parents’ sub-optimal behaviour, so that poverty would indicate, literally, that if you weren’t a bad person then probably your mother was. And this political notion was mediated not just through women’s bodies but through our actual tits. It was faintly chilling for all women, mothers or not. It would be wonderful if the RCM’s humane, good sense intervention marked the end of it.