The election of Hassan Rouhani as the new President of Iran has stunned everyone.
I talked to the head of his campaign two days before the election who believed his man had enough momentum to get through just the first round of voting, but he voiced little optimism beyond that.
His supporters on the streets of Tehran are stunned. Many never expected their votes to be counted at all, never mind to count in electing their candidate as the new President.
The other candidates, who Rouhani trounced, have not been seen in public since the election.
All were more hardline, most ultra loyal to Iran's Supreme Leader. One can only imagine their thoughts about the cleric who came from nowhere to beat them.
The world outside Iran is surprised. No-one expected that the Supreme leader Ayatollah Khamanei would allow a moderate to occupy the Presidency at a time when Iran is under pressure, under sanctions and under suspicion.
But nowhere is the shock of Rouhani's election more profoundly felt than in Israel.
The country's Prime Minister Benjamin Netanyahu spoke twice in the days after the election, warning the world that Iran's new face changed nothing. "The election", he said, "clearly reflects the deep disaffection of the Iranian peope with its regime, but unfortunately it doesn't have the power to change Iran's nuclear ambitions".
Israel has been deeply concerned about Iran's growing ability to process its own uranium. It has argued that Iran is on the verge of being able to produce enough to make its own nuclear weapon. The fact that President Ahmadinejad, the man who said Israel should be wiped off the map, is leaving, doesn't change Israel's profound anxiety about its future survival. So Israel has been threatening to bomb Iran, if Israel's own, unspecified "red line" is crossed.
But now it has a problem.
The election of a moderate, who is promising to open a new chapter in Iran's relations with the outside world and who says Iran will be "more transparent" about its nuclear programme, rather pulls the rug from under the tough talkers in Israel.
It will be hard, for a few months at least, for Israel to get a hearing. Few will want to listen to its talk of "all options, including the military one, must be on the table". Netanyahu knows he will struggle to be heard, for a while at least.
He is asking the world now to focus on Iran's known, core ambition of nuclear independence. "People have to be consistent", he argues, "they have to see the important thing. And the important thing is, does Iran veer away from that, that is does it make a U-turn and go the other direction. Not whether it smiles or presents this or that more respectable face. What it does, not what it says it will do."
Paradoxically, Israel had one of its best cards in the figure of Mahmoud Ahmadinejad. When he cast doubt on the Holocaust and said Israel should be wiped of the face of the earth, leaders and people around the world were shocked. How could anyone do a deal with, even talk to, a President who said such things?
Anyone in the United States suggesting it would be shouted down. President Obama in extending his hand to Iran, bypassed Ahmadinejad altogether. Israel knew the more Ahmadinejad ranted, the better it was for it, as the world saw clearly how unreasonable Iran was.
Now he's leaving power and things have changed.
Israel knows Rouhani's election is a moment of hope, a time for cautious optimism, perhaps an opportunity for a new and successful round of talks on the nuclear issue.
It also knows Rouhani is a wily negotiator. When he was his country's chief nuclear negotiator from 2003 to 2005, he kept Iran's nuclear programme going without sanctions being imposed and without Iran being referred to the United Nations Security Council.
Now, simply by being there, by smiling as he did so much in his first news conference, Rouhani presents Israel with a problem.
Repeating the same old phrases about the clock ticking and military options won't be enough for Israel now.
Not for the first time in recent years, events in the Middle East, this time in the form of yet another new leader, are forcing Israel to rethink its tactics and its priorities.