Israeli Defence Minister Ehud Barak's abrupt retirement from politics caused a shock to the general election campaign but left many predicting his immediate return to office.
Barak, 70, said in Tel Aviv he would not seek re-election in January and would retire when a new Government was formed, probably in three months.
He has held the role for seven years, completing three terms under three governments and was Labour Prime Minister from 1999 to 2001.
Barak said he wanted to spend more time with his family and had now had enough of politics, "something for which I never had any special desire in the first place ..."
Barak unseated Benjamin Netanyahu in 1999, but the two formed a close partnership after Netanyahu's re-election as Prime Minister in 2009. The former rivals were united in military policy.
Barak, Israel's most decorated soldier and a former military chief-of-staff, deepened co-operation with the US military to new levels in the past five years. The army was transformed into a high-tech powerhouse, most recently revealed in its Iron Dome missile defence shield.
Right-wingers in Netanyahu's Likud Party were unable to contain their glee at Barak's departure. Environmental Protection Minister Gilad Erdan said Barak's political and ideological path had been misguided.
Hamas spokesman Fawzi Barhoum said: "Barak's retirement reaffirms that the Israeli Government failed to achieve any of the goals of [the Gaza attack]."
Sceptics noted that polls predicted Barak's Independence Party would be wiped out in January's ballot, and he was more likely to remain a minister by being appointed from outside the political system. They recalled that the last time Barak retired to spend more time with his family in 2001, he divorced his wife, made millions in defence-related business deals, and soon returned to politics.
"Ehud Barak is as likely to sit at home and write a memoir as Vladimir Putin is likely to take up synchronised swimming. Barak left a political stage that was not working in his favour and opened up another that just might," mused Amir Mizroch, editor of the English edition of the Israel Hayom daily.