It's no surprise that the Italian
investigation into the killing of a senior secret service agent should have arrived at very different conclusions from the American one.
There has been a public outcry over the death of Nicola Calipari
Nicola Calipari was shot by American soldiers near Baghdad airport on 4 March.
Calipari was escorting the Italian journalist Giuliana Sgrena, just freed from being held hostage, out of the country.
The American report, though it contains deleted references to poor communication, clears the soldiers of wrongdoing.
Approaching an American roadblock is one of the more nerve-racking things you have to do in Iraq.
Once you have spoken to the US soldiers on duty and managed to establish your good faith, things are easier, even for Iraqis.
But the worrying time is as you drive up to it. The soldiers are understandably nervous, looking for any sign that your vehicle may be a suicide bomb.
If the road through the checkpoint is complicated or badly marked and you make a mistake of some kind, then you are in real danger of your life.
Once, near a big American installation, I watched an old man in a beaten-up car, with an equally old wife in the front seat and a child, perhaps their granddaughter in the back.
An American soldier waved at him to stop, but the old man panicked and managed to get into a completely wrong lane.
The soldiers immediately started shouting and waving their guns at him, and the old man stalled his car.
There was more excited yelling, but in English, which only seemed to confuse the old man further.
As I stood there watching, it seemed inevitable that someone was going to be killed.
It was only when an Iraqi translator ran over and calmed the soldiers down that the tension eased.
You can't really blame the soldiers. The violence against them is growing almost daily. They understand little of the country they are in, and usually none of the language.
The Italian report into Nicola Calipari's death puts it this way: "It is likely that the state of tension, stemming from the conditions of time, circumstances and place, as well as possibly some degree of inexperience and stress, might have led some soldiers to instinctive and little-controlled reaction."
Recently, when I went through an American checkpoint in Baghdad and we had just started to relax again, I glanced at my companion, a long-serving soldier in the British army, now working as our security adviser. He was visibly angry.
The Americans, he said, had no idea how to run a roadblock. It was badly sited and poorly protected.
No wonder, he said, they take so many casualties.
"They ought to get out and patrol the roadsides, and take the war to the other side, instead of sitting there and waiting to be attacked."
There was a time when the British army behaved like that in Northern Ireland: jittery, resentful, too quick to fire, an easy target.
Thirty-five years ago, in Belfast and Derry, I saw British soldiers behaving just as aggressively towards local people as the Americans do in Iraq.
Checkpoints have been targeted by suicide bombers
That was before it dawned on the British army that if they treated every passer-by as an enemy, it wouldn't be long before every passer-by was an enemy.
The army's eventual success against the IRA in Northern Ireland owed a great deal to this basic change of attitude.
Yet it isn't just at the level of the ordinary soldier at the roadblock that the campaign has to be waged.
Some senior US officers understand this fully. Lt Gen David Petraeus, for instance, an impressive man who is now in charge of training the Iraqi police and army.
I spent some time at a US base to the north of Baghdad with one of his top men, a highly intelligent US Marine colonel, Dave Flynn, who had a clear appreciation of the way this war in Iraq might be fought successfully.
Holding to account
But for Iraqis, the daily problems at roadblocks continue.
The killing of Nicola Calipari was only a better publicised example of what usually happens when American soldiers kill someone by accident - there is a brief internal enquiry, which tends to find that the action was justified. End of story.
Some of the worst "friendly fire" cases of the 2003 invasion were never properly investigated. The killing of the British ITV television team, headed by the distinguished reporter Terry Lloyd, for instance.
When 18 people, including my Kurdish translator, were killed in a bombing incident during the invasion, we were assured that a proper investigation would be held.
Nothing more has ever been heard about it
If American soldiers, understandably nervous and rarely trained for the job of patrolling foreign streets, know that even if they kill a man as prominent as Nicola Calipari, nothing will happen to them, it is scarcely much of an incentive to be careful.
The British army learned a difficult and sometimes painful lesson in Northern Ireland about operating successfully in a hostile environment.
Holding ordinary soldiers, the unfortunate grunts on the front line, to account for what they do is a part of it.
But there has to be a change of attitude at the top as well.
Read John Simpson's previous columns:
You can't compare Iraq to Northern Ireland. Do they have suicide bombers driving around Northern Ireland? It's easy to criticize the road block procedures when your life isn't on the line.
Don, Minneapolis, MN, USA
John Simpson, and all the other anti-American correspondents like himself, have failed to question the honesty of Giuliana Sgrena whose hatred of the USA is well-known.
Navi Reyd, Toronto, Canada
I am currently working as a security operator in northern Iraq and have previously worked in the Baghdad area. I agree all sides are nervous about checkpoints but the rules are simple, slow down well in advance, use any local protocols for identification and show yourself if possible. So blaming the soldiers after what I have read is not possible.
The Americans are claiming that satellite monitoring of the vehicle shows it was moving at 60mph. It's surprising that Mr Simpson doesn't address this is his article.
A Montford, Kinross
Having served with the UN and NATO and seen US soldiers in Somalia and Bosnia, I have to agree with Mr Simpson. The US soldiers are way behind their British colleagues in the way the handle the 'natives'. If you are not able to treat the population well you will be hated by them.
Ulf Larsen, Moss, Norway
Our present United States administration seems to loathe learning from the experience of others. Mr Simpson's article is a wonderful suggestion of how we could greatly increase our possibilities of success while reducing our casualties. If only we knew enough to listen.
Jim Curry, Cut Bank, MT, USA
Articles like this are the main reason I read the BBC news. Intelligent, thoughtful, reasoned analysis.
Clif Emery, Chicago, IL
Always thoughtful and intelligent, Mr Simpson's writing and reporting is an example of how good journalism can be and should be.
Jeremy Smith, Itzig, Luxembourg
I'm astounded at the near complete lack of insight from the author and commentators here alike. If the author had any degree of integrity at all, he would mentioned that US satellite photos have proven that Sgrena's car was travelling at over 60mph.
Jon Davison, Sheridan, Indiana, USA
Simpson's is a thoughtful analysis. Cash's is an unfortunate comment. The soldiers have a duty to restore hope and mend broken lives. Just shooting to kill is murder. Little wonder they are losing the support they deserved at the collapse of Saddam Hussein. If they do not change methods and treat people humanely, they will suffer defeat like in Vietnam.
Maxime N Compaore, Ouagadougou, Burkina Faso
This is a sensible balanced report which actually contains some very good advice about working to move the Iraq situation forward and improving the value of US troops on the ground. I hope this report is available in Italian and Arabic.
Malcolm Parker, Basingstoke
I note that only American solider who has been convicted of murder during the whole Iraq war is one who killed American soldiers. Anyone else has no value. I feel for Calipari but I feel more for the hundreds of faceless, nameless, valueless Iraqis murdered at these checkpoints.
Simon, Wellington, New Zealand
In as much as I'm a serviceman, I believe there are lots of young soldiers that are put in harm's way. Their judgement and thinking because of stress has caused lots of wrongdoing on the front line. I hope the US can have the enlistment age increased to 21. I believe that will help in the positive handling of combat situations.
Frank Taylor, Cincinnati, OH
Mr Simpson's comments hit the nail right on the head. The "long serving British officer" mentioned should be approached by the Americans to set up a desperately needed training system for them. The sad fact is that Americans are among the kindest, nicest people in the world, yet they are almost universally hated, because of their seriously flawed foreign policies and actions.
Geoff M Stead, Orillia, Ontario, Canada
Reading the American responses to this article worries me even more than the article itself! Dave M shocked me the most - justifying current US point and shoot tactics by comparing what he would have done in Vietnam could not be a worse example. How, exactly, did it help the US in any way then, and why should it help them now?!
Al, Newtonmore, Scotland
Dave M from the USA completely misses the point when he tells John Simpson to give up the day job. John Simpson is merely expressing the fear which all Iraqis feel when approaching a road block. Why should they feel fearful of these liberators/outsiders when in their own country? This also seems to be the typical reaction of the US government when confronted with an experienced well thought out comment on their behaviour in Iraq.
Ben Smith, London
John Simpson puts his finger on exactly what is wrong with US tactics. As he rightly says, you can't blame the soldiers, but rather their training and lack of experience. What sets this article apart is that it actually provides some possible answers. Accountability is paramount. So is adequate training by those who've dealt with this kind of insurgency before. The US have to stop shielding their troops from any and all blame if things go wrong, otherwise they will continue to be trigger happy.
Jim Moores, London, UK
If one had approached a check point that I manned in Vietnam at more than five mph, I would have killed them, friend or foe. Neither I nor my successors in the current military should be asked to accept any iota of risk beyond that imposed by duty in a war zone. They are not there to gamble. They are there to live and to kill all those that may jeopardise that goal. Accordingly, there is no lesson to be learned from this situation.
Harry Cash, Chicago, IL, USA
Soldiers are not to blame indeed for these accidents. Some are kept on duty in Iraq way over their enrolment period. Some are just too young and inexperienced, not trained enough to be assigned to such delicate missions. The blame for all this should go directly to the high military command that lets this happen! That's the people who should be put on trial (along with Private England) for prisoner abuses, for breaches of rules of engagement, etc.
OHM, Marlborough, MA. USA
The impunity of trigger happy US soldiers, and the lack of meaningful, independent investigations of the many incidents when they torture or kill, set a frightening precedent, and is making us enemies around the world. Only US deaths are investigated. Non-US life has no value to the US military, and the concepts of justice and accountability seem lacking entirely. How can I feel proud of this?
Michael, San Francisco, USA
Really don't know who is to blame for this killing, but if inexperience and stress led some US soldier to "instinctive and little controlled reaction", what led the Italian service to go fast at night time on the most dangerous road in Baghdad, using a rented car? Why not wait until the morning after and use an escorted convoy? This should be a show of experience?
Marco Ferri, Rome, Italy
I have to disagree with John Simpson. Our soldiers wouldn't have needed to be in Iraq if it wasn't for the likes of Saddam Hussein, Musab Al-Zarqawi, and the other usual bunch of thugs. Mr Simpson, if you feel nervous approaching an American checkpoint, why are you a war correspondent? Give up the day job. That's fine by me.
Dave M, Tonopah NV USA
A very good article, it hits the nail on the head. I would have used stronger wording perhaps, but then I am not a respected journalist. I would say that the American military is basically incompetent, because they have concentrated on technology to the exclusion of the human element. This policy backfired in Vietnam (which was a mistake for other reasons also) and it is currently backfiring in Iraq. Let us hope that Mr Simpson will succeed in persuading a few of the decision-makers to start thinking, instead of just reacting.
D Fear, Heidelberg, Germany
I may even agree (almost) totally with this article, but the point is: who is going to tell to the Americans to change attitude?? The UN? Or Mr Blair? We do not have to forget that the American government (with the typical arrogance of winners) does not care about what other countries may suggest. Bush said clearly that America does not need to be authorised by anybody to strike. In fact America did it ignoring the Security Council's decision on the Iraq war. So in reality there is no chance they will change attitude. So why bother?
The skill level the Americans exhibit is the same as they exhibited in Vietnam. In Vietnam they were afraid to mount active night perimeter patrols and their bases were vulnerable mortar fire etc. Their Australian allies in Vietnam mounted active patrols and denied the enemy the opportunity to fire into their camp. A checkpoint is an opportune static target and is subject to manipulation in many ways.
Poor Calipari had to lose his life in his noble duty to save the lady he had gotten freed. But this is more the fault of US troops who are trigger happy and racially biased against the locals. His life cannot be brought back. Not with all the gold in Fort Knox. He lives in the past. Let's say he once lived and he only lived once.
Edgar Martins, Toronto, Ontario, Canada