A key ally of embattled Syrian dictator Bashar al-Assad who'd been invited to be a panelist at a Washington forum on peace in the Middle East may no longer be welcome now that video has surfaced of him threatening to unleash suicide bombers in the U.S. and around the world.

Ahmad Hassoun, Syria's grand mufti -- or highest-ranking religious official, was invited to take part in the Foundation for Middle East Peace's (FMEP) June 28 event, dubbed "Coexistance and Dialogue in Syria." But furious ex-pat groups immediately raised a fuss, accusing Hassoun of being an Assad apologist and directing event organizers to a YouTube video of him warning the West to mind their own business as Assad carries out a bloody crackdown on rebels that has so far left an estimated 20,000 dead.

"I say to all of Europe and to the U.S.: We will prepare martyrdom-seekers who are already among you, if you bomb Syria or Lebanon," Hassoun says in the video.