The prospect of a Syria free of chemical weapons would be a great relief to Israel, a neighbor long seen as the main target for Syria's arsenal, built up over decades. Further, many Israeli experts said Wednesday, the deal presented by Russia, in which Syria would relinquish its stockpile of such weapons, could become Exhibit A for how a credible military threat by the United States — something Israel's leaders have ardently urged against Iran's nuclear program — could force the hand of a reluctant and adversarial government.
But there was also pessimism in Israel that the Syrian president, Bashar al-Assad, would actually fulfill his promise to turn over and ultimately destroy his chemical stockpile. Instead, many analysts worried that Mr. Assad, his Iranian patrons and the Lebanese militia Hezbollah would emerge strengthened, and that the main upshot of the episode would be a sense of American wavering on involvement in the Middle East.