After a while in every conflict, in each rebellion, during every disaster, we begin to fall into a daze of detail. An event that detonated into our lives begins to grow familiar. Like the wallpaper in our sitting room, we know it is there, we can describe its patterns, but we cease to focus on it quite so intently.

But then the hum of news is slammed into sharp focus by a single event that puts a human face on history. It is almost always a tragic face.

From the mist of pages of news, of round-the-clock news bulletins, emerges an image that becomes an icon. The nameless student taunting that tank in Tiananmen Square. The photograph of a young girl running naked down a road after being severely burnt by a napalm attack in South Vietnam. The death of Jan Palach, the Czech student who committed suicide by setting himself alight in January 1969 in Wenceslas Square to protest against the Soviet-led invasion of Czechoslovakia. The haunting vision in 1992 of the semi-naked, skin-and-bones internees of the prison camp run by Bosnian Serb forces in Omarska. Earlier still there was the image of the suffragette Emily Wilding Davison throwing herself before King George V’s horse Anmer at the Epsom Derby in 1913.

In Iran this week that face belongs to Neda, a young woman apparently felled by a sniper from the pro-government Basij militia. Amateur video footage of her murder has become a funnel through which all the world’s outrage against the oppression of Tehran’s reigning mullahs is being poured. Neda has given resistance a face.

The footage is already among the most viewed clips on YouTube. Thousands have written online tributes to Neda. Posters of her bloodied face have been held aloft by protesters in Los Angeles and New York. Overnight “I am Neda” has become the rallying cry of the protest movement, echoing the solidarity of those Roman slaves who claimed, one after the other, “I am Spartacus”.

Neda’s fame marks the moment when Iran’s repression emerged from the forest of newsprint and became personal. We are all Iranians now.