The truth is like any casualty of war: it dies on the direct orders of military leaders. This was as true a century ago as it is for those fighting today in Ukraine, Syria and the Gaza Strip. After a reception in 1917, far from the waking nightmare of the Western Front, David Lloyd George told the editor of the Manchester Guardian, “If people really knew [the truth], the war would be stopped tomorrow . . . but, of course, they don’t know and can’t know.”

The reception was held in honour of the war correspondent Philip Gibbs, who knew precisely what was happening in France and Belgium but had been threatened with death by firing squad if he filed one more uncensored report. At the front, Gibbs lived as a fugitive, in almost as much danger from his own side as from the German troops. Today, in our rituals of public remembrance, one of the many things we try to forget is that our government did its best to keep the horror of the trenches off the front pages.

This summer marks the centenary of a war that triumphalist historians insist on calling “great”. Millions of paper poppies, thousands of melodramatic memoirs and a century of royalty looking sad in expensive hats have not done away with the central obfuscation: that this was an epic f***-up. The First World War should not have happened. Those millions of men and women did not have to die. Their deaths were not inevitable – they were extremely evitable and were resisted on all fronts, particularly by workers’ movements, which did more than anyone else to end the bloodshed.

If national leaders want to justify retroactively the pointless slaughter of millions of largely working-class men and women by telling us that they died “for our freedom”, it’s up to them. Families need comfort but not as much as governments need to save face and exploit our natural sympathy with fallen soldiers by claiming that it was all for a good cause – and, after all, we won.

If we want to pretend that the bloodshed of the First World War had a positive impact on the lives of the working class in Britain and elsewhere, rather than simply being the worst thing white people did to one another in centuries, that is cowardly but comprehensible. What we should not do is further dishonour the memory of the fallen by calling these rites of organised historical reimagining “remembrance”.

Away from the trenches, official censorship was also used to keep incompetent generals in their jobs. On one grubby, stuck-together page of this disregarded chapter of journalistic history, a young Australian reporter was entrusted with a letter to the British prime minister. The letter, from another journalist, detailed the bloody blunders of British and Allied commanders but it was confiscated when the young reporter was detained by his own side and he was obliged to rewrite the letter later from memory. The reporter’s name was Keith Murdoch and he went on to found a media empire and father Rupert Murdoch, who also disdains all state propaganda in which he has no personal financial interest.

Philip Gibbs, meanwhile, submitted to censorship in order to keep filing wartime reports. They make fascinating reading, as much for what they don’t say as what they do. The British are always advancing, when they are not making jolly jokes to a reporter, and the death of a British soldier is always brave and meaningful rather than panicked and unnecessary.

If there are eyeless, staring corpses leering out of the rotten mud, they belong only to the enemy. Gibbs described, in his scathing postwar memoir Now It Can Be Told (1920), how he had to travel with official censors, whose duty it was to “examine our screeds with microscopic eyes and with infinite remembrance of the 1,001 rules . . . Was it permissible to describe the smell of chloride-of-lime in the trenches, or would that discourage recruiting?”

On the centenary of the First World War, we must remember that millions who died had little idea what they were signing up for – nor how their deaths would be treated 100 years later, in patriotic ceremonies replete with expensive light shows and ceremonial flower-planting, while the international arms trade remains healthy. We will be treated to the weary insistence that numberless soldiers “sacrificed” themselves – or, more accurately, were sacrificed – to protect the people of Belgium, and not because, as Philip Gibbs wrote, “England knew that her imperial power would be one of the prizes of German victory.”

It is to protect this patriotic vision that journalists were considered no better than spies in the war years – and war reporters and whistleblowers today are treated as “terrorists” for exactly the same reasons. From the al-Jazeera journalists imprisoned in Egypt to Chelsea Manning, those who seek to tell the truth about war are persecuted for betraying the interests of nations, which are not at all the same as the interests of ordinary soldiers and civilians.

When it comes to human history and especially the history of war, we do not tell it as it was – rather, we tell it as we are. And right now, we are a society whose stewards have an appetite for tragedy but no desire to end it, whose leaders refuse to acknowledge that some sacrifices are simply not worth making – not then, not now and not ever.

In the words of the “last fighting Tommy”, Harry Patch: “The politicians who took us to war should have been given the guns and told to settle their differences themselves, instead of organising nothing better than legalised mass murder.”

The truth about the First World War is still buried in an unmarked grave somewhere on the fields of France and a century of bloodshed later, it behoves us to remember it in more than empty ceremony.

Laurie Penny is contributing editor of the NS