The murder of four residents of the Beit Hagai settlement on the dark, winding road from Hebron was almost expected - as was the settlers' reaction.
Just two days earlier, the IDF Chief of General Staff, Lieutenant General Gabi Ashkenazi, had met the commanders of the Judea and Samaria Division and warned them to be on the look-out for attempts to disrupt the opening of the direct peace talks in Washington.
The warning was two-fold. Palestinian organisations, especially Hamas, may try to divert attention from the talks and harm the position of President Mahmoud Abbas by carrying out terror attacks.
On the other hand, the Jewish settlers may try to cause provocations in the West Bank, with similar intentions, reminding Prime Minister Binyamin Netanyahu of the challenge awaiting him at home if he agrees to extend the settlement freeze after the 10-month moratorium ends later this month.
Both scenarios are now unfolding.
The past two years have been the quietest period in memory in the West Bank, with the number of serious terror attacks down to a bare handful. Hamas's infrastructure has been significantly eroded following the assassinations and arrests of most of its local leadership, and continuous IDF and Shin Bet operations.
There has also been an improving level of co-operation with the Palestinian Authority's new American-trained security forces, who are as anxious as the Israelis to deny Hamas a foothold.
But the murders of Yitzhak and Tali Aimes, Kochava Even-Haim and Avishai Shindler on Tuesday evening prove that the Hamas cells have not been totally eradicated, and show just how fleeting is the sense of security.
One senior officer said this week: "Ultimately, it is all a matter of luck. Hamas tried half a dozen times to carry out similar attacks but it isn't that easy to hit a moving car at night when you are also sitting in a moving car.
"If they had shot and missed, it would have barely warranted a mention on the news. They succeeded this time and everyone is up in arms. It can happen again and again, every time we seem to be on the brink of a diplomatic breakthrough."
The military wing of Hamas took responsibility for the attack, promising: "It is only the first of a series of operations."
There is little doubt that the movement will use every opportunity to remind all sides that it is not to be pushed out of the picture. The PA responded to the shooting by arresting 100 local Hamas members, but this will do little to deter them.
The news of the attack caught up with Mr Netanyahu while he was on the plane to Washington. "I have ordered the security forces to act without any diplomatic constraint," he said.
Naftali Bennett, formerly Mr Netanyahu's chief of staff and today the managing director of the settlers' Yesha Council, had a more resolute answer. As far as the settlers are concerned, order or no order, the building freeze is over. "The moment we finish burying our dead, full building activity will resume," he said, hours after the attack.
So far, the prime minister has yet to announce his policy on the future of settlement building after the moratorium ends in three weeks' time.
His original plan had been to keep quiet on this until the very last possible moment, but events may yet force his hand.
● Ron Prosor, Israel's ambassador to Britain, has said the direct talks "absolutely represent a real chance of peace".
During a phone conference with international media on Wednesday, Mr Prosor said: "It reminds me of the Muppets Statler and Waldorf. If you sit on the balcony shouting, it's a lousy show. With all the cynicism and low expectations, we should say thank you to President Obama and the American people, who are trying to facilitate both sides reaching something."