When Israeli and Saudi officials publicly acknowledged their quiet thawing of relations in 2015, the U.S. and other Western allies were encouraged. Yes, the Middle East was unraveling elsewhere, but two longtime foes were making common cause against Iran.

This cold peace has its benefits. But in the last year, a darker side has come into focus.

Consider a Palestinian blogger and journalist named Iyad Al-Baghdadi, now living in exile in Norway. Last month he disclosed that Norwegian authorities informed him that he was a target of Saudi Arabia, which used a powerful Israeli-made cyberweapon to hack his phone. Al-Baghdadi worries that his life could be in danger from Saudi operatives.