JERUSALEM – Israeli Defense Minister Ehud Barak abruptly quit politics Monday, potentially robbing Prime Minister Benjamin Netanyahu of a key ally who enabled his hard-line government to present a moderate face to the world.

Netanyahu’s party picked a young, more hawkish list of candidates in its primary election Monday.

Barring another comeback by the mercurial former general, Barak’s departure marked an end to a distinguished career that spanned half a century. It began on a communal farm, led to military greatness and business success and a mixed record in politics.

Despite polls showing his small centrist Independence Party gaining momentum after the eight-day Israeli offensive in Gaza that he steered, Barak said he would not run again for office in the Jan. 22 elections.

“I feel I have exhausted my political activity, which had never been a special object of desire for me,” Barak, 70, said in a surprise announcement in Tel Aviv. “There are many ways for me to serve the country and society, not just through politics.”

Barak will remain as defense minister until a new government is sworn in after the elections.

Still, analysts predicted that Israel’s most prominent warrior-statesman of his generation was perhaps still angling to keep his job after the election as a special appointment of Netanyahu, who is expected to be re-elected.

“He’s not as popular as an electoral candidate as he is a minister of defense,” said Shlomo Avineri, a political science professor at Jerusalem’s Hebrew University. “He’s not going to say no if he’s asked to be the next minister of defense. And he probably will.”