What is it that compels a man to force himself on someone who resists him in no uncertain terms, often till the last breath? A sense of misplaced entitlement? A monstrous sense of depravity? Sexual frustration? Class aggression? Gender hatred?
From celebrated cases like that of Dominique Strauss-Kahn, accused of forcing himself not only on a hotel maid in New York but a legion of other women throughout his career (including the teenaged daughter of a family friend), to the recent case of the 22-year-old migrant worker in Delhi who brutalised a five-year-old girl and left her to die, there lies a universe of sexual assaults: marital rape, date rape, prison rape, gang rape, incestual rape, child sexual abuse and war rape, amongst others.
For most women, especially those brought up as baby boomers born at the height of the feminist movement, rape is a bewildering and deeply disturbing reality. Because for years the women's movement had attempted to bequeath to women the concept that not only their minds but also their bodies were their own - their own to care for, fulfill and honour.
The act of rape attacks the very principle of the tenet that a woman's body is of her own provenance. And in this way it seeks to overturn the very canons of the women's movements.
And perhaps therein lies the answer to why men rape. Far from being an act of sexual aggression, it is, in fact, a collective and evolutionary war on women, an attempt to turn back the hand of time to an age when men could dominate and manipulate what they assumed was the weaker sex.
Which is why I feel the primeval battle of the sexes is being fought one rape at a time, and leading it are the rapists themselves - the battle's first stormtroopers. These are men who brutalise women and try and convey to them that they have no rights at all, not even the most basic - the right to their own bodies.
The message of rape is this: you have no rights of your own, not to be born if we so deem; not to the same education, food and opportunities as your brothers; not to choose your career or life partner; not to dress the way you like or travel where you want. And, of course, not to say no to us in any form or on any occasion.
Rape is one half of the population's way of teaching the other half a lesson for daring to attempt to empower itself.
Almost a century after the first wave of feminism that focused on suffragette and property rights and 50 years after voices such as those of Gloria Steinem and Betty Friedan rose to address other issues of gender inequality and injustice, and after women have achieved some measure of recognition (but far from enough), rape appears to be the most insidious and diabolical form of suppression.
It's a universal and evolutionary gender war fought one Nirbhaya at a time.
Which is why when women storm the barricades, scream for justice and weep for each new rape victim, they cry not only for her, but for themselves and their own threatened status.
They ask not who the rape victim is - for in a larger sense they know it is themselves.