It was the horse that I noticed first. I could see its agony, escaping as a shrill bray from its agape mouth, with its teeth and tongue exposed, its head craned upwards, eyes wide in horror. The same agony is echoed in the wail of the mother, on the left-hand side of the canvas, crying to heaven for the dead child in her lap – but crying in vain, for it was from that heaven that the bombs dropped. The same perpendicular scream is mirrored on the other side of the canvas, a man unable to escape what appears simultaneously as a burning house and a monster, engulfing him with teeth of flames.

Until I first saw Pablo Picasso’s Guernica at the Reina Sofia in Madrid a few years ago, I had only known it as a black, white and grey oblong, the way it appears in art reference books. I never had more than a passing interest in Picasso or cubism, so it was his more colourful works, his Weeping Woman or the Demoiselles d’Avignion, that came to mind when I thought about the artist.

But when I entered the Guernica room at the Reina Sofia, my periphery disappeared and the painting filled my entire field of vision. Measuring over three metres tall and over seven metres wide, Guernica certainly justified in having an entire room at the Reina Sofia to itself. Far from being a static black, white and grey oblong, Guernica was a dynamic scene, a scene of complete devastation, without a glimmer of hope, filled with the debris of war, bodies piled in darkness. I stood and looked. I watched the painting unfold. I watched the child die; I could see the spear plunge through the horse; I saw the flames licking the man’s flesh. It’s the only painting that’s ever brought me to tears.

The scene that Picasso depicts is of the destruction of the Basque town Guernica by German and Italian bombers on behalf of Franco on 26 April 1937, during the Spanish Civil War. For three hours, the town of 7000 people was subjected to wave after wave of carpet-bombing, resulting in more than 1500 dead. At the time, Franco denied any involvement, suggesting that it was the Basques and Republicans themselves who were to blame. It became clear, however, that the orders to bomb the town did come from Franco and that the bombing of Guernica was a way of demoralising the Basques and the Republicans.

There is an obvious comparison between Guernica 1937 and Gaza today. Many in the media have the connection: they are both politically-motivated rather than strictly military campaigns, subjecting the civilian population to an intense and merciless punishment.

The imagery coming from Gaza reinforces the parallels.

Allison Deger, assistant editor at Mondoweiss, recently published in a post some of her own photographs from Gaza. She noticed the injuries inflicted not just on humans but also on Gaza’s animal population, specifically its horses and donkeys. Mondoweiss editor Phil Weiss points out the striking similarities between Deger’s dead and wounded animals, and Picasso’s wounded horse. Both are covered in grey, mouths frozen in a scream, eyes open. American socialist Scott Johnson wrote in 2007 that ‘no horse could ever look so contorted and terrified as the one in Guernica’ – yet here we see it again, in Gaza 2014.

Picasso wrote that a painting is not ‘interior decoration’ but ‘an instrument of war’. The images we see from Gaza today as a result of Israel’s bombing offensive – a dead horse frozen in terror; a boy’s body on a beach, his leg twisted at an impossible angle; a girl’s body wrapped in a white shroud, only her face poking out so her mother can kiss it one last time – these are also instruments of war. Benjamin Netanyahu recognises it when he brands the slain Palestinians as ‘telegenically dead’.

The images become instruments because Israel is waging its own war: not just Protective Edge but a campaign to dehumanise the Palestinians to such an extent that children, infants, pregnant mothers, the disabled and the elderly lose their innocence, so that they are no longer victims but are instead legitimate targets.

Guardian columnist Suzanne Moore wrote that the proliferation of graphic images from Gaza, particularly on social media, was part of a ‘competitive outrage’, writing: ‘I don’t need to you to tweet them to show me you care.’ But as Haidar Eid, the associate professor at al-Aqsa University in Gaza, wrote for Al Jazeera: “The footage of headless toddlers, has … become the direct message that Palestinians want to use to convey: ‘This is our daily political reality.’”

Whether it’s misrepresenting an obliterated Gaza neighbourhood and calling it Israel, refusing to even present the Palestinian death toll at all, or shouting down Palestinian voices in live interviews, the media has often been an accomplice in the distortion of the truth around Israel’s war crimes, not just now but during all of Israel’s wars against its neighbours. This is unsurprising given that the mainstream press is owned by a handful of corporations with an interest in propping up American imperial interests.

Even during ‘peaceful’ periods, Israel is obsessive about the images of itself that are transmitted and works with mainstream media outlets (up to and including celebrity blogger Perez Hilton) to ensure that its depiction accords with their specified brief: a Mediterranean getaway; a gay ‘Mecca’ (a particularly absurd appropriation of language); a bastion of liberal values in, by implication, a sea of Arab backwardness. In 2005, the Israeli state worked with American PR execs to launch ‘Brand Israel’, because, according to the Foreign Office, it would ‘rather have a Style section item on Israel than a front page story’.

The images we have today of weeping mothers, blood-soaked medics, the bombed-out schools and the lifeless horses tell a different story. As Picasso’s Guernica has become a universal symbol of the atrocity of war, these images from Gaza are now a part of the historical record, a symbol of the inhumanity of the Israeli state. The sharing of these images by people with limited means of resistance is a way to undermine Israeli propaganda, albeit slowly, like waves breaking on a limestone cliff. Eventually, this monolith, too, will crumble.