Lebanon ? Israel ordered its embassies on high alert and the FBI put U.S. terror squads on guard to protect Jewish institutions after Hezbollah’s leader vowed Thursday to retaliate anywhere in the world for the assassination of one of its top commanders.

“Zionists, if you want this kind of open war, let the whole world listen: Let this war be open,” Hassan Nasrallah told a throng of fist-waving mourners who attended the funeral of Imad Mugniyeh, the mastermind of terror spectaculars that claimed hundreds of American lives.

Nasrallah’s fiery speech signaled the Iranian-backed Shiite group was ending a yearslong policy of battling Israel only on Israeli or Lebanese territory, raising the specter of attacks in Western or other countries.

Hezbollah and its Iranian backers blamed Israel for Mughniyeh’s death in a car bombing Tuesday in Damascus, the Syrian capital. Israel denied involvement.