Last Friday afternoon my BBC colleagues and I filmed at the Baghdad city mortuary.
Baghdad's mortuaries act as a barometer of the violence
A few months ago we would have done it as a matter of course. But now the security situation in Baghdad is so bad that we had to plan our trip with some care.
The mortuary has been the subject of a good deal of controversy.
The Washington Post reported that 1,300 bodies had been taken there since the upsurge in sectarian violence which followed the bombing of the Shia shrine at Samarra on 22 February.
A former UN official said that many of these bodies showed signs of torture and summary execution.
By contrast the US commander in Iraq, Gen George W Casey Jr, insisted that there had been no great increase in the amount of communal violence and that the number of deaths was probably around 350.
At the mortuary itself, the guards showed us a large refrigerator truck, parked alongside the building, which they said had been provided by the Americans because of the overflow of bodies from the mortuary itself.
Today the situation in Iraq is worse than at any time since the fall of Saddam
And during the 20 minutes we filmed there, three more bodies were brought in.
This is purely anecdotal evidence, of course. Journalism is an art, not a science, and everyone knows how inaccurate it can often be.
Yet the big advantage of being a journalist is that you can go out and see things for yourself.
That's not easy in Baghdad nowadays - though this in itself is evidence of the way things are deteriorating here. But experience has encouraged me to believe the journalists, not government officials, at times of trouble like this.
Doom and gloom
In 1978, as the revolution in Iran unfolded, it was clear to those of us who spent our days out in the streets, seeing the mounting violence for ourselves, that the demonstrators were losing their fear of the Shah and his forces.
Diplomats missed signs in the run-up to the Iranian Revolution
At the time I often used to visit the highly intelligent and generous British ambassador in Tehran at the time, Sir Anthony Parsons. He insisted that the Shah would survive, and he assured the British government that this would happen.
Afterwards, with characteristic honesty, he wrote a book about why he got it wrong. The main reason was that his information came from the Shah's own ministers. It was too dangerous for his own diplomats to spend much time in the streets, finding out what was happening.
But the journalists could see for themselves that the revolutionaries were building up an unstoppable momentum.
It gives me no pleasure today to forecast further doom and gloom here in Iraq. But, as in Iran in 1978, the facts on the street contradict the assertions of the generals, the politicians and the diplomats.
Ever since the invasion in 2003, you have been more likely to turn out right if you were pessimistic than if you were an optimist. At the end of 2003 a well-known columnist wrote with immense assurance that there might be a spike of violence until early 2004, but that afterwards the trouble would die away. He could not have been more wrong.
Slow political progress has encouraged the insurgents
Coalition officials assured us that the elections in January and December last year would result in a down-turn in the number of killings and bombings. They were wrong, too. Today the situation in Iraq is worse than at any time since the fall of Saddam.
It might be different if the politicians who were elected in the December election could agree to form a government. So far, though, they haven't made much progress.
The caretaker prime minister, Dr Jaafari, is increasingly unacceptable to the Kurds and to most of the Sunnis, as well as to the Americans. So far, though, no likely candidate has emerged from the Shia majority to take his place.
Now some senior Iraqi politicians are saying it could be June or July before a government is formed.
It matters, because the absence of effective government is a real encouragement to the insurgency.
Just over a year ago, in the wake of the January election, the level of violence dropped noticeably, and the generals and politicians in London and Washington allowed themselves to think that the insurgency might have been defeated.
Ordinary people have become targets
Not so: the insurgent leaders were worried that the Iraqi people had been mobilised against them by the success of the election, and they were waiting to see what was going to happen.
But it took three months before a government was formed. Public opinion was alienated, and the insurgency was soon more effective than ever.
This time, the politicians are taking even longer to get their act together. And in the meantime the worst of the violence is directed, not at the Americans or the British, nor even at the Iraqi police and army, but at ordinary worshippers at Sunni and Shia mosques.
The level of sectarian violence has dropped off a little in recent days. But Iraq hasn't turned a corner, and it doesn't even look like turning one.
If there is a good reason to be a bit more optimistic, I haven't spotted it yet.
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