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 and tumultuous 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 that was highlighted by failed peacemaking efforts during a brief term as prime minister.