They number at least 400,000, a significant proportion of them hardline religious Jews who have little time for realpolitik or compromise. They believe they are doing God's work in settling land that was promised the Jews in the Bible.
"Enough with the embraces and love," Oz Kadmon from Kafr Darom said. "[Prime Minister Ariel] Sharon is a belligerent man and he must be addressed in the language he understands."
Kfar Darom is one of 21 settlements due to be evacuated this summer after the Israeli government voted last week to pull out of Gaza.
And Kadmon is no young firebrand: he is a father of six and a senior official in Sharon's own Likud party. But like many other settlers he is resorting to threats of violence against Israeli leaders that have been taboo since the assassination of a previous prime minister, Yitzhak Rabin, by a fanatical young settler in 1995.
Flurry of threats
"Why is it taboo to talk of transferring Arabs, yet the government of Israel is now preparing to uproot thousands of Jews and destroy their homes?" 44-year-old Eve Harowe, who moved to the West Bank settlement of Efrat, near Bethlehem, from Los Angeles 17 years ago, said.
"All of this land is for the Jewish people and must never be surrendered."
The strength of the settlers' opposition to the "disengagement", as Sharon's plan for the withdrawal from Gaza is officially known, can be gauged by a sudden flurry of death threats and hate mail being directed at senior politicians and army commanders.
Israel's cabinet has approved the
plan to give up Gaza settlements
One, Brig Gen Ilan Paz, head of the civil administration in the West Bank, received a letter warning him that he would suffer death by "amputation", a Biblical punishment. Shaul Mofaz, the defence minister, was sent a meat hook through the post.
Sharon himself has had to hire security guards to protect his late wife Lily's grave at his Sycamore ranch in the Negev, after letters from extremists warned that they would desecrate it.
Walls across the country are daubed with death threats, bumper stickers read "Lily is waiting for you", and montage photographs are circulating of the Israeli prime minister dressed as Stalin above the words "The Dictator".
Similar photographs of Rabin, showing him in a Nazi uniform, appeared shortly before his assassination. His killer objected to the Oslo accords signed by Rabin which handed over control of cities in the West Bank and Gaza to the Palestinians.
Already the government has called up hundreds of reserve soldiers and policemen and is preparing to deploy 18,000 to enforce its decision.
Ultra-Orthodox Jews are leading
the charge against Sharon's plan
But what disturbs many ordinary Israelis is the possibility that the evacuation will trigger a civil war in which soldiers and policemen sent to clear Gaza will face a dangerous confrontation with militant settlers.
Most of the nearly 200 settlements in Gaza and the West Bank are effectively small armouries that have been generously supplied by the Israeli army for three decades. Men wander around with automatic rifles slung over their shoulders, and women keep a pistol within arm's reach in their cars and homes.
The Yesha council, which represents settlers in the West Bank and Gaza, says resistance must be non-violent. It is formulating a legal strategy for opposing the disengagement with the help of former senior army officers who live in the settlements.
They have been devising ways to bypass police road blocks to bring as many as 100,000 demonstrators into the Gaza Strip.
But already, five months before the evacuation begins, there are signs of a split in the settler leadership. A letter written by one regional council head, Pinhas Wallerstein, to his residents tells them: "If there is a need, we will not hesitate and we will lay our lives on the line to fight the evacuation."
At a settler conference in Jerusalem on Thursday, leaflets were handed out observing that each settlement had "more weapons, ammunition and skilled individuals than during the Warsaw ghetto uprising". Official banners read: "Sharon, you are bringing a Holocaust upon us".
More worrying than the inflated language, however, are signs that shadowy groups of militant settlers are making inroads into the mainstream of the settler community as it grows increasingly disillusioned with governmment policy.
What worries Israeli officials are
militant elements among settlers
Leading the way is a group known as the "hilltop youth", teenage children who have been setting up dozens of isolated outposts of a few caravans across the West Bank. Attempts by the government to dismantle them in 2002 led to vicious fights between the youngsters and soldiers.
Since then the hilltop youth have been attending summer camps where they have been trained by a militant group called Fortress of Judea, itself a front organisation for the outlawed Kach movement.
Kach subscribes to the racist ideology of the late Rabbi Meir Kahane, who demanded the forced expulsion of all Arabs from the Holy Land.
The first signs that militant settlers are seeking a violent confrontation with the government have come in past few weeks.
Shortly before the disengagement vote, groups of hardliners, including many teenagers, took over road junctions across Israel at rush hour, burning tyres, scrawling on walls "Rabin is waiting for Sharon", and throwing stones at police cars.
Ten police officers were injured, and at least 50 arrests followed. One 17-year-old girl interviewed later on Israeli television said: ''I would be happy if Sharon was dead.''
Jerusalem's al-Haram al-Sharif is
seen as a possible militant target
Uncharacteristically, Israel's internal security service, the Shin Bet, received no advance warning of the disruption. Undercover agents, according to reports, have repeatedly failed to infiltrate the extremist settler groups.
Last week it also emerged that at least 500 hilltop youths had infiltrated Gaza with fake ID cards. The army was planning to seal off the strip before the evacuation to prevent precisely such an occurrence.
Guy Kotev, an Israeli radio reporter with contacts with the settlers, said that no one could be sure what they were planning as they were refusing to talk to outsiders. "When I ask them where they'll be on disengagement day, they do not reply," he said. "They are very suspicious."
Acts of betrayal
Despite the secrecy surrounding these activities, a clear trail leads to one of their main authors, a extreme young religious settler from Hebron called Itamar Ben Gvir. His 17-year-old wife, Ayalah, was among those arrested during the road junction protests.
Ben Gvir has hardly been out of the Israeli media since he recently pushed his way towards the education minister, Limor Livnat, shouting that he would hound all the supporters of disengagement.
"Why is it taboo to
talk of transferring Arabs but the government of Israel is now preparing
to uproot thousands
of Jews and destroy
Eve Harowe, US-born West Bank settler
Later, on Israel Radio, he said government ministers were engaged in acts of "betrayal", code among the settlers for treason punishable by death.
Ben Gvir is considered one of the senior figures in Kach, the organisation behind the training of the hilltop youth. In a recent interview he said: "They should know getting the nation of Israel out of Gush Katif [the largest Gaza settlement] means you will need to prepare a lot of coffins."
He and a handful of other well-known extremists were recently reported to have established a new far-right underground organisation. Ben Gvir boasts that it has several thousand members sworn to secrecy who are interested in "intensifying" the settlers' protests.
What will such a struggle consist of? Another Kach leader, Noam Federman, says resistance will not necessarily take place inside Gaza if it is sealed off by the army.
Some settlers have issued death
threats to senior Israeli leaders
One option, he says, would be to launch an attack on the most sensitive religious site in the Holy Land, al-Haram al-Sharif, which Jews call the Temple Mount.
Currently it houses several mosques, including the Dome of the Rock, a site revered by Muslims as the place where the Prophet Muhammad ascended to heaven. Israel stakes a claim to the area, saying it is built over the remains of the destroyed Second Temple.
Extremist Jewish groups want to bomb the mosques and build the Third Temple, to herald the arrival of the Messiah. Some believe that an attack against the holy site would foil Sharon's disengagement by plunging Israel into an armed standoff with its Arab neighbours.
That is also the fear of the police, who have asked for an extra $13 million to protect al-Haram al-Sharif during disengagement.
"The real struggle will take place in Jerusalem and other places across the country," Ben Gvir said, "and that has the possibility to ultimately thwart the plan."