The government had given the impression that it would start gently, by sending in teams of surveyors.
Instead four bulldozers, surrounded by soldiers and police, with a military helicopter clattering overhead, started cutting an access road through the brown earth beside the football field of the Palestinian village of Zur Bahir.
In a few weeks, Israeli contractors will have stripped Har Homa, known to Palestinians as Jabal Abu Jhneim, of its trees, which make the hill look like a long, green island stretching between Jerusalem and Bethlehem. When the building project is complete, Har Homa will become home to some 27,000 Jews in 6,500 apartments, isolating Palestinian districts in Jerusalem from those outside.
A mile away, and out of sight of where Israeli bulldozers were starting to work on the northern end of Har Homa, Faisal Husseini, the Palestinian leader in Jerusalem, had established a small camp of six tents beside a half-built house on a neighbouring hill from which he was orchestrating protests. "We are trying to say to Israel that the peace process is dying," he told a crowd of reporters and supporters who had clambered up the hillside through driving rain to stand outside his tent.
Israel had originally said it wanted Mr Husseini off the hill by morning and if he did not go its forces would remove him. But, perhaps reflecting that such a confrontation, conducted before a dozen television cameras, could only benefit Mr Husseini, the dozen Israeli troops near his tent, huddled in a house to keep out of the rain, made no effort to dislodge him. Nevertheless, Mr Husseini said: "They are pushing us from being officials and negotiators to becoming [political] activists."
Overnight, Yasser Arafat, the Palestinian leader, had refused to meet Benjamin Netanyahu, the Israeli leader, to discuss concessions to the Palestinians, such as opening of a port and airport at Gaza, as a quid pro quo for the building of the settlement at Har Homa.
"No trade," said Abu Alaa, a chief Palestinian negotiator, who had joined Mr Husseini in his tent. He said the concessions Israel was now offering it had already agreed to make as part of the interim peace agreement signed in 1995. Salah al-Taamari, the most important political leader in Bethlehem, said it would be difficult for Mr Arafat to meet Mr Netanyahu now, because he was "so arrogant, so rude, so racist".
Despite the verbal clashes, both Israelis and Palestinians were being restrained on the ground. Although there were reports of Israeli troops massing around Har Homa yesterday morning, they were difficult to find on the ground. Close to the most likely confrontation point there were only about 200 soldiers. As night fell, Palestinian boys from the nearby Christian town of Beit Sahour started throwing stones at Israeli troops on the road to Har Homa but the soldiers did not respond.
The ground-breaking by the Israeli bulldozers was out of sight of the Palestinian towns to the south. Three Israeli Arabs trying to demonstrate were hit by rifle butts, but otherwise there was little violence.
Reasons for this restraint include the rain and the belief that confrontation over Har Homa will go on for a long time. But the biggest motive is that both sides are conscious the world is watching. Palestinians feel that Israel is isolated as never before. They think that if Palestinians were seen to start violence then they might forfeit international sympathy.
Mr Netanyahu yesterday evening accused Mr Arafat of aiding potential bombers by releasing a senior Hamas leader. Mr Arafat, for his part, has ordered Palestinian hospitals to get beds ready, though he probably wants to squeeze the maximum political advantage out of the crisis over Har Homa without provoking a confrontation which he would be unable to control.
At the same time there are so many points of friction between Israelis and Palestinians on the West Bank that as the political temperature rises it will probably be impossible to avoid a clash leading to heavy casualties.