The work of Michael Hastings, who died at the age of 33, led to the downfall of an American military hero.
Michael Hastings was - to put it gently - a divisive figure.
His profile of General Stanley McChrystal, which appeared in Rolling Stone in 2010, exposed a secret world of military officers.
Hastings apparently did not email quotes to public-affairs officials to get their approval, as many journalists do. Instead he quoted from casual conversations among military people - and showed how they trash administration officials.
One officer, for example, refers to Vice-President Joe Biden as "Bite Me".
When President Barack Obama saw the piece, he was understandably peeved. McChrystal, the top Afghanistan war commander, was soon out of a job.
On Tuesday Hastings was killed. His vehicle ran into a tree in Hollywood, according to media reports. His award-winning work about McChrystal and other officers leaves an impression, however, and will long outlive him.
The ousting of McChrystal in 2010 had far-reaching implications - for military strategy in Afghanistan and also for the world.
McChrystal had at the time been pushing for a more ambitious effort in Afghanistan, rather than the scaled-back campaign favoured by Obama and Biden.
Once McChrystal was gone, the situation was clear. Obama was in charge, and troops would soon start to come home from Afghanistan.
The controversy over Hastings' article shed light on how the president and his national-security advisers perceived the war in Afghanistan - and also how Americans saw themselves and their military leaders.
Before Hastings' article appeared, generals were lionised.
Journalists portrayed General David Petraeus, for example, as tireless and lean, a larger-than-life scholar-warrior. When McChrystal took over as commander in Afghanistan, he also made a splash.
The 6ft 1in, 178lb McChrystal was actually thinner than Petraeus and slept less, three hours a night. (He also loves Monty Python, he once told me in an email).
Because of the adoring press, the legend continued. Journalists portrayed McChrystal as "a modern combination of saint and ninja", wrote Hastings in The Operators.
People wanted to hear stories about how McChrystal was 10ft tall and "chewed through wires", as one person, a friend of mine who knows McChrystal well, recalls.
In truth McChrystal is extraordinary - in battle and in meetings. But he is not endowed with magical power.
Instead, as my friend explains, McChrystal pays attention to details. He gets up early on the day of an important meeting and reviews the names of people who will attend.
Yet acknowledging that McChrystal works hard to memorise names - and is human - means ordinary people could do the same.
"Nobody wants to hear that," says my friend.
This willing suspension of disbelief also takes place on a large scale. When generals are invincible, so is the US. Therefore ordinary Americans can sit back and wait until the wars are done.
Hastings' reporting went against the grain, showing that generals are flawed.
"Hastings' hallmark as reporter was his refusal to cosy up to power," writes Tim Dickinson in an obituary that appeared in Rolling Stone.
Through his reporting, Hastings exposed the danger of elevating a rogue player such as McChrystal, who had previously worked in black operations, to the job of war commander, a position that requires not stealth and cunning, but diplomacy.
Hastings also made things harder for journalists.
After the Rolling Stone article appeared, officials restricted the access that journalists had once enjoyed. So some reporters hated Hastings.
Even people who admire his work, though, were put off by some of its aspects.
In I Lost My Love in Baghdad, Hastings wrote about his girlfriend, Andi Parhamovich, an NGO worker who was killed in Iraq in 2007.
The title puts Hastings, not Parhamovich, at the centre of the story. According to the New York Times, the book is deeply flawed.
Hastings described a moment "when life was good, when I was in Baghdad with Andi and my career was skyrocketing and I was writing stories about the war".
In The Operators, Hastings adopted a similar "I-Am-Awesome" literary style.
The book opens in a house in upstate New York's Adirondacks area. Hastings was smoking a cigarette and talking on the phone with one of McChrystal's advisers.
"I put the smoke out in an empty citronella candle, went inside, and grabbed a notebook from the kitchen counter," Hastings wrote.
This less-than-riveting scene characterises the book, which seems hastily written and cobbled together in a clumsy manner.
Hastings had plenty of weaknesses, ranging from a penchant for stilted prose to a vaulting ambition.
Yet he has left an important legacy. His reporting altered the way that people in the military and the media see themselves.
Because of his work, officials and journalists are somewhat more realistic, and humble, about their bosses and jobs, as well as about the role that the US plays on the global stage.
This shift in perception may not change the world. But it is a step in the right direction.