The killing of Hamas’ leader Yahya Sinwar is a major symbolic and military victory for Israel a year after the hard-line ideologue masterminded a devastating terrorist attack that shattered the country’s sense of security.

But it’s unclear whether Sinwar’s demise will open the door to the release of Israeli hostages still held by Hamas, end the war in Gaza or defuse the broader tensions between Israel and Iran, former U.S. officials and regional analysts said.

Having severely weakened…