'We acknowledge," the letter says, "that violence has claimed the lives of many thousands of Iraqi civilians over the last five years, either through terrorism or sectarian violence. Any loss of innocent lives is tragic and the Government is committed to ensuring that civilian casualties are avoided. Insurgents and terrorists are not, I regret to say, so scrupulous."

This quotation comes from the Ministry of Defence's "Iraq Operations Team, Directorate of Operations" and is signed by someone whose initials may be "SM" or "SW" or even "SWe". Unusually (but understandably), it does not carry a typed version of the author's name. Its obvious anonymity – given the fact that not a single reference is made to the civilians slaughtered by the Anglo-American invasion and occupation of Iraq – is no surprise. I, too, would not want to be personally associated with such Blair-like mendacity. What is astonishing, however, is that this outrageous letter should have been written this year.

I should say at once that I owe this revelatory text (actually dated 20 January) to a very un-anonymous Independent reader, Tom Geddes, who thought I would find its "economy with the truth" interesting. I certainly do. We are now, are we not, supposed to be in the age of Brown-like truth, as we finally haul down the flag in Basra, of near-certainty of an official inquiry into the whole Iraq catastrophe, a time of reckoning for the men who sent us off to war under false pretences. I suspect that this – like the Obama pretensions to change – is a falsehood. Well, we shall see.

Mr Geddes, I hasten to add, is a retired librarian who worked for 21 years at the British Library as head of Germanic collections and is also a translator of Swedish – it turns out that we share the same love of the Finnish-Swedish poet Edith Sodergrund's work – and he wrote to the Ministry of Defence at the age of 64 because, like me (aged 62), he was struck that John Hutton, the Secretary of State for Defence, described those who jeered at British troops returning home as "cretins".

"Such jeering is clearly not meant to denigrate individual bravery and sacrifice," Geddes wrote to Hutton on 28 October – readers will notice it took the Ministry of Defence's "SM" (or "SW" or "SWe") three months to reply – "(but) is a political comment on the general dubious legality and morality of recent military actions."

I'm not so sure the jeering was that innocent, but Geddes's concluding remark – that "unless you or the Government can explain and justify Britain's war activities, you cannot expect to have the country on your side" – is unimpeachable.

Not so "SM's" reply. Here is another quotation from his execrable letter. "It is important to remember that our decision to take action (sic) in Iraq was driven by Saddam Hussein's refusal to co-operate with the UN-sponsored weapons inspections... The former Prime Minister has expressed his regret for any information, given in good faith, concerning weapons of mass destruction in Iraq, which has subsequently proven to be incorrect."

I am left breathless by this lie. Saddam Hussein did not "refuse to co-operate" with the UN weapons inspectors. The whole problem was that – to the horror of Blair and Bush – the ghastly Saddam did co-operate with them, and the UN weapons team under Hans Blix was about to prove that these "weapons of mass destruction" were non-existent; hence the Americans forced Blix and his men and women to leave Iraq so that they and Blair could stage their illegal invasion. I saw Blix's aircraft still on the ground at Baghdad airport just two days before the attack. Note, too, the weasel words. Blair did not give his information "in good faith", as SM claims. He knew – and the Ministry of Defence knew (and I suppose SM knew) – they were untrue. Or "incorrect" as "SM" coyly writes.

Then again: "We can assure you that the Government would not have engaged in military action if it were not satisfied that such a decision was justified and lawful. The former Attorney General, Lord Goldsmith, confirmed on 17 March 2003 that authority to use force against Iraq existed from the combined effect of UN Security Council Resolutions 678, 687 and 1441."

But as an outraged Tom Geddes points out in his reply to this remark, "You must be aware that the decision to wage war on Iraq was neither justified nor lawful. The Attorney General's advice has been widely described as 'flawed'. Given that his previous advice was that an attack would be unlawful, we all know what 'flawed' means. I suspect the MoD (Ministry of Defence) also knows." So do I.

I'm also sure that this is a standard "reply sheet", sent out to all dissenting English people. The sentence "millions of Iraqis now live free of Saddam's oppression and have control of their own destiny" is pure public relations – not least because it fails to mention that up to a million Iraqis have not been able to control their own destiny since 2003 because they happen to be dead as a result of our invasion.

There's a lovely bit at the end of "SM'S" 's letter where he (or I suppose it could be a she) says that "our brave servicemen and women ... are ... preparing Basra airport for transfer to Iraqi control..." Well of course they are, because – since their own retreat from Basra city -- Basra airport is the only square mile of Iraq in which the British are still in occupation.

The letter ends with "SM'S" 's surely sublime hope that this "letter goes some way to addressing your concerns" and I can only repeat Tom Geddes' reply: "I am grateful for the length of your response, but shocked by its contents." So am I. No doubt, when the Brown Government – or the Cameron government – holds its inquiry into this illegal war, "SM" will re-emerge as a witness or at least a spokesperson. By then, I suppose the "Iraqi Operations Team" will have been closed down – even, perhaps, by then transmogrified into the "Afghanistan Operations Team" with a parallel set of historical lies – but I trust there will be a retired librarian on hand to point this out.