JERUSALEM — Israeli officials remained silent on Thursday about their airstrike in Syrian territory the day before, a tactic that experts said was part of a longstanding strategy to give targeted countries face-saving opportunities to avoid conflict escalation. But Syria’s own confirmation of the attack, followed by harsh condemnation not only by Israel’s enemies Iran and Hezbollah but also by Russia, may have undercut that effort, analysts said, increasing the likelihood of a cycle of retaliation.