But if Barak was unpopular with the public, he retained his clout with Netanyahu, whom he commanded in an elite special operations unit. As the prime minister's point man with the United States, Barak was welcomed in Washington as a moderating influence on Netanyahu's hard line policies toward the Arab world and Iran's nuclear program.
That alliance saw some rocky times recently with reports the prime minister objected to Barak's newly moderate tone that Israel should defer to the U.S. in deciding whether to attack Iranian nuclear facilities.
But the two seemed to have patched up things, appearing to work harmoniously on the recent Gaza campaign.
In a statement Monday, Netanyahu said he "respected" Barak's decision.