Journalism will kill you but it will keep you alive while you're at it, said one Horace Greeley, 19th century founding editor of The New York Tribune.

It could be the epitaph for brave, beautiful, barmy Marie Colvin, the celebrated foreign correspondent, who was killed by a rocket attack in the besieged Syrian city of Homs yesterday.

One fellow journalist described her as "a real life Katharine Hepburn but braver and funnier". Another, The Herald and Sunday Herald's David Pratt, adds his own tribute on our obituaries page.

For weeks now the Leveson Inquiry into media ethics has been exposing the deeply ingrained grubby underbelly of the Fourth Estate. Reading the testimony of its witnesses, it is easy to be deluded into believing that all journalism is tawdry and self-seeking.

As the website of the Reporters Without Borders pressure group points out, at least five journalists have died in war zones already this year. That doesn't include French photographer Remi Ochlik, killed at Ms Colvin's side, nor the veteran American journalist Anthony Shadid, whose funeral took place in Beirut yesterday, after he collapsed while working in Syria last week. Last year 66 journalists died in the line of fire, 16% up on 2010, thanks to the Arab Spring.

Such journalism is getting more dangerous. Once respected as neutrals and needed by both sides in conflicts to get their message across, war reporters could count on special protection. Now every crackpot faction has its own website and the press are often regarded as targets. The killers are rarely brought to justice, so corrupt governments and shady militias operate their own form of brutal censorship with impunity. Yet we need those prepared to tell the truth about war, with all its contradictions and ambiguities, those capable of giving its victims a voice.

With her honey blonde hair and piratical eye patch – the result of losing an eye while reporting on the Tamil Tigers – Ms Colvin was a well kent face.

What she did so well was follow with passion and persistence an honourable tradition of women's journalism including that of Lady Sarah Wilson's reports from the Boer War, Martha Gelhorn's unflinching dispatches from the Spanish Civil War and Clare Hollingworth's vivid accounts from the Second World War.

My own brief experience suggested that being a woman in conflict zones has advantages. In Somalia, I was treated like an honorary man by the men and one of the girls by women who would never have spoken to a guy. To catch a visceral sense of life in a war zone requires empathy, another area where women have the edge. What's the appeal? Perhaps it is that people are at their most impressive when they are most vulnerable.

Of course, some of these correspondents are thrill-seeking war junkies but they are the exception. Despite her reputation for being first in and last out of a conflict, Ms Colvin tried to weigh risk, seeking the line between bravery and bravado, the fearless and the foolish. At a service in 2010 to remember journalists killed in conflict, she said: "Our mission is to report these horrors of war with accuracy and without prejudice. We always have to ask ourselves whether the level of risk is worth the story."

Last year Reporters Without Borders protested that a crackdown on the media in Syria meant nobody knew what was going on in places like Homs. Jerky mobile phone footage and desperate bloggers are no substitute for professional authenticated eye-witness reporting. As journalists began to be smuggled into these communities, the sickening truth started to emerge, confirming the West's worst fears. As a result pressure is now mounting on the regime of Bashar al-Assad.

With typically black humour, Mc Colvin's last words to a friend were: "I think reports of my survival may be exaggerated". Tragically, she turned out to be right.