BY any country's standards, the horror of what happened in Delhi on December 16 would merit some serious soul-searching.

A 23-year-old woman and a male friend were picked up by a private bus after a trip to the cinema. They were assaulted by a group of men on the bus in a sustained attack lasting about an hour – the woman was serially raped and beaten so badly with an iron rod that she would later die of her injuries. She was then tossed out naked onto a flyover.

Five men have now been charged with murder, gang rape, attempt to murder, kidnapping and a string of other offences. There is talk of chemical castration and the death penalty. A sixth is likely to be tried in a juvenile court.

But, more significantly, across India in these past few weeks there has been an outraged wave of protests. And it is the anger expressed in these demonstrations that has made the country take pause as much as the chilling and barbaric crime itself. That rage tells us that India thinks it has a rape problem.

According to Indian women's rights lawyer Flavia Agnes: "Rape is a cultural thing in India; just as US has gun culture, we have this."

Her provocative comment explains why this particular rape caused a national reaction somewhat akin to that seen in the United States following the recent primary school shooting: for India, this is part of a long-running story.

Those men and women who have howled their anger in the past two weeks have done so not just because of what happened on that bus, but because of the countless horrific cases that came before; because of media investigations that have shown how police blame women for sexual attacks; because of research that has demonstrated that hundreds of men accused of sexual violence towards women have been allowed to stand in Indian elections in the last five years; because, in the north-western state of Haryana, following an apparent epidemic of rapes, politicians and community leaders excused it, saying that much sexual violence was consensual.

According to another lawyer, Madhu Mehra: "The system thrives on the good and bad dichotomy of women. In Delhi, women live with a curfew sanctioned by the chief minister of Delhi, who says that women should be home by a particular time, because she cannot secure the streets. Women have to live with an enormous amount of calculation: should I go out, where should I go, what should I wear? This is a situation very similar to terrorism."

The Delhi gang-rape case may have awoken the rest of the world to the fact that India considers itself to have a rape problem, but anyone who had been listening would have known this beforehand. The question is: why now, why this particular crime?

There have been others as brutal and horrible – just last week saw the sentencing to death in Kerala of a man for raping a 15-year-old girl while she was home alone.

But there were factors in the Delhi case that gave it a kind of horrific clarity. It was a stranger rape, whereas most rapes are committed by a friend, neighbour or relative. It was also difficult to blame the woman herself for the fact that she was repeatedly raped and beaten with an iron rod, since she had got into the bus at 9pm following a trip to the cinema and a male friend was with her, and had tried to defend her. Blaming her would suggest that going out anywhere was "asking for it". But also, many women related to the victim because, although she was not wealthy, she was "a striver" – she was a paramedic.

As the country's government rushes to put together new anti-rape laws, the bigger question is whether the death of this young woman can be a trigger for change. Many are sceptical as to whether a law will change anything. The overwhelming message seems to be that what is needed is a change in culture.

As Flavia Agnes put it: "There is a whole culture of teasing women in our society - cracking jokes, saying ill things about women. It's as if men must prove their manhood by indulging in it - We must learn to respect women in our society."