Ordinary Israelis are therefore being conscripted into an army of spin-doctors in a campaign termed “hasbara” – Hebrew for “public diplomacy”, or more literally “propaganda”.

In the latest offensive, the education ministry has launched a compulsory hasbara course for Israeli students travelling abroad. All youth delegations are now required to learn how to justify to outsiders Israel’s policies in the occupied territories. According to officials, the students must challenge those who “seek to delegitimize Israel”.

It is yet more evidence that hasbara has become a national obsession in Israel – and that the line between support for one’s country and support for the subjugation of another people has been erased. Some 85 per cent of Israelis tell pollsters they are keen to become hasbara ambassadors for the Netanyahu government.

A hasbara ministry already targets the international media with good news, while cultural events from food fairs to Israeli entries at film festivals are designed to prove that Israel has another, hidden side.

For years the Israeli government has relied on paid workers – and thousands of volunteers in Israel and abroad – to surf the net posting pro-Israel comments.

At Israel’s international airport, Israeli holidaymakers are offered brochures explaining the importance of persuading those they meet that Israel is misunderstood. Advice suggests emphasising successes such as Israel’s invention of drip irrigation and popular varieties of the cherry tomato.

And yet the latest hasbara drive is as unlikely to reverse Israel’s slow slide into ignominy as its predecessors.

The hasbara industry’s chief flaw, as Israeli political scientist Neve Gordon observes, is its assumption that “the merchandise is fine, and only the packaging needs to be replaced”.

But rapid developments in information technology mean Israel has less control over its image than ever before.

First it was 24-hour rolling news, then the internet. Now cheap smartphones make every Palestinian a potential documentary-maker, ensuring that moments of cruelty and oppression are captured and available for anyone who cares to look.

Palestinians post online videos of their everyday abuse: from demolition of homes to stone-throwers being shot with live ammunition; from settlers burning crops to children being dragged by soldiers from their beds in the middle of the night.

Last week 56-year-old Zaki Sabah, a familiar cake vendor in Jerusalem’s Old City, starred in one such video. Bystanders filmed him being savagely beaten by Israeli police on a busy road. Denied a permit for many years by the occupation authorities, Sabah has been repeatedly fined and jailed.

Meanwhile, another video exposed Israel’s deceitful account of its supposedly peaceful interception of a boat trying to break the Israeli blockade of Gaza. As more than a dozen passengers were held captive over the weekend, footage was smuggled out showing that Israeli commandos had electrocuted some of them with tasers during the takeover.

Troubling imagery is not restricted to the occupied territories. Film of the charred interior of a historic church next to the Sea of Galilee highlighted last month the latest hate crime by Jewish extremists against Israel’s large Palestinian minority.

The futility of trying to staunch the tide of evidence damning Israel on media old and new was exemplified last week by Moshe Yaalon, the defence minister.

“There is no humanitarian distress in Gaza,” he averred, while the media illustrated reports of his speech with pictures of mountains of rubble and children still homeless a year after Israel’s massive assault on the besieged enclave.

Yaalon’s sophistry may placate Israel’s diehard supporters but the rest of us are more often incensed by such insults to our intelligence.

The hasbara offensive is doomed for another reason.

With the Palestinians’ case substantiated by evidence, rather than Israel’s, the evangelists of hasbara have only one recourse: to blame the messenger.

Critics of Israel, it is implied, are either inveterate dupes or unabashed anti-semites. Either they have been deceived by the Israel-haters, or they are haters themselves.

As the hasbara industry moves into overdrive, such slurs are becoming all too common – including against those Israel most urgently needs to cultivate as allies.

Judith Nir Mozes, the wife of interior minister Silvan Shalom, a Netanyahu confidant, possibly reflected high-level thinking in Israel when she tweeted last month a racist “joke” about President Barack Obama. “Do u know what Obama Coffee is? Black and weak,” she wrote, ridiculing the leader of Israel’s most important ally.

Similarly, the Israeli foreign ministry hurried to mock foreign journalists, even though they are hasbara’s target audience.

In a short animated video, a naïve reporter is shown claiming that the people of Gaza simply want peace as militants fire rockets just behind him. Next the reporter misidentifies Hamas’ tunnelling as the “first Palestinian subway system”. The video ends with a warning: “Open your eyes, terror rules Gaza.”

Michael Oren, Israel’s recently departed ambassador to the US, has joined the fray too, castigating American Jewish journalists as “self-haters” for their critical coverage of the Israeli prime minister.

Hasbara’s cartoon version of reality is not only unconvincing but, in alienating friends as much as foes, self-defeating. Netanyahu may hope to repackage Israel, but his product – ongoing oppression of Palestinians – is one few can be persuaded to buy.

Jonathan Cook won the Martha Gellhorn Special Prize for Journalism. His latest books are “Israel and the Clash of Civilisations: Iraq, Iran and the Plan to Remake the Middle East” (Pluto Press) and “Disappearing Palestine: Israel’s Experiments in Human Despair” (Zed Books). His website is www.jonathan-cook.net.

A version of this article first appeared in the National, Abu Dhabi.