It always starts with words. Genocide is largely remembered for its depraved acts, but it is incubated in language. Words can cast dark spells on a population, stirring hatred in those who otherwise see themselves as moderate, humane, normal.

This is why the genocide convention of 1948 criminalises “direct and public incitement to commit genocide”. Like Britain, Israel was a signatory nation and, two years later, it translated the convention into domestic law. There were four acts, it decreed, that leave the offender “treated like a person guilty of genocide”: one is “incitement to commit genocide”.

As the British lawyer Daniel Machover tells me, Israel has a legal obligation to prosecute those who incite genocide. But instead, since the grave war crimes committed against Israeli civilians by Hamas and other armed groups on 7 October, government ministers, parliamentarians, army officers and journalists have indulged in the language of extermination. This chilling phenomenon has few historical precedents, because usually instigators of genocide go to great lengths to cover up their crimes. As Raz Segal – an Israeli-American associate professor of genocide and Holocaust studies – tells me, Israel’s onslaught on Gaza is unique “in the sense of discussing it as what I think it is – that is, genocide – because the intent is so clearly articulated. And it’s articulated throughout Israeli media and society and politics.”

In South Africa’s document setting out its genocide case against Israel over the Gaza war, there are nine pages dedicated to genocidal incitement. It notes that Benjamin Netanyahu twice “invoked the Biblical story of the total destruction of Amalek”, declaring: “You must remember what Amalek has done to you, says our Holy Bible. And we do remember.” A later passage in the Bible leaves no doubt for interpretation: “Now go and smite Amalek, and utterly destroy all that they have, and spare them not; but slay both man and woman, infant and suckling, ox and sheep, camel and ass.” This was no throwaway comment. Consider the unprecedented slaughter of Palestinian children – or “infants and sucklings” – and note that six days after invoking Amalek in a national address, Netanyahu referred to it again in a letter to army soldiers and officers.

Then there’s Isaac Herzog, the Israeli president, who declared: “It is an entire nation out there that is responsible. It’s not true this rhetoric about civilians not aware, not involved. It’s absolutely not true.” No demarcation between militants and civilians exists here. Yoav Gallant, the minister of defence, was a repeat offender. On 9 October, in an unashamed commitment to collective punishment, he declared Israel was imposing a “complete siege on the Gaza Strip. There will be no electricity, no food, no fuel, everything is closed,” he said. “We are fighting human animals and we are acting accordingly.”

On witnessing Israeli soldiers gleefully destroying civilian infrastructure on TikTok, some have speculated there has been a breakdown in army discipline. More likely is that soldiers listened when Gallant informed troops he had “released all the restraints” and “lifted all restrictions” on Israeli forces.

Another senior official, Israel Katz, now minister of foreign affairs, declared last year when he was energy minister: “All the civilian population in Gaza is ordered to leave immediately. We will win. They will not receive a drop of water or a single battery until they leave the world.” Meanwhile the heritage minister, Amihai Eliyahu, opposed humanitarian aid on the grounds that we “wouldn’t hand the Nazis humanitarian aid”. He also suggested nuking Gaza, declaring “there is no such thing as uninvolved civilians”. That saw him suspended by Netanyahu.

Some army officers are willing participants. In a video addressed to Gaza’s residents, one major general, Ghassan Alian, castigated “citizens of Gaza” for celebrating Hamas’s extremism, promising: “Human animals are dealt with accordingly. Israel has imposed a total blockade on Gaza, no electricity, no water, just damage. You wanted hell, you will get hell.” Another retired major general and adviser to the defence minister, Giora Eiland, demanded other countries be prevented from offering assistance, demanding that Gaza’s people be left with “two choices: to stay and to starve, or to leave”. He advocated Gaza being made “a place that is temporarily or permanently impossible to live in”, declared women were not innocent because “they are all the mothers, sisters or wives of Hamas murderers”, and advocated “humanitarian disaster” and “severe epidemics” to achieve war aims: the finance minister Bezalel Smotrich tweeted he agreed “with every word”.

South Africa’s document is incomplete: there have been countless new examples since it was published. After the Israeli attorney general reportedly issued a warning to colleagues to “watch their words”, clearly concerned that Israel was being incriminated on the eve of the international court of justice investigation, the Knesset deputy speaker, Nissim Vaturi, doubled down on a previous assertion that “Gaza must be burned”.

Netanyahu is said to have warned his ministers to “be sensitive”, yet each day brings more examples of genocidal intent and incitement. This should define media coverage, and yet still the fantasy that this is a war against Hamas – with a side debate about proportionality – is indulged. Without western support, Israel’s mass slaughter would immediately end. This is why we must address complicity: lives depend on it.

That is not simply to critique those who still cheer on this abomination, who if we lived in a society that valued human life, would, by now, be considered morally depraved beyond redemption. As Jean-Paul Sartre once declared: “Every word has consequences. Every silence, too.” Here is one of the great crimes of our age, unfolding before our eyes, described to me by the Palestinian activist Omar Barghouti as “the world’s first livestreamed genocide”. Rarely has a crime so grave been so honestly spelled out to the world by its architects. Yet many of those who rightly and passionately condemned the atrocities of Hamas have little or nothing to say about Israel’s actions, despite the direct involvement of our own rulers. This is obscene – and occasional handwringing will not scrub away the shame. Tacit acquiescence allows the horror to continue. Words can be dangerous, but so too can their absence.

Owen Jones