BEIRUT -- Tensions over the Israeli airstrike on Syrian territory appeared to increase Thursday, as Syria delivered a letter to the United Nations declaring its right to self-defense, and Israel's action was condemned not only by longstanding enemies, including Iran and Hezbollah, but also by Russia.
Israeli officials remained silent about their airstrike inside Syria the day before, a tactic experts said was part of a longstanding strategy to give targeted nations face-saving opportunities to avoid worsening a conflict. But Syria's own confirmation of the attack may have undercut that effort.
"From the moment they chose to say Israel did something, it means someone has to do something after that," said Giora Eiland, a former head of Israel's National Security Council and a longtime military leader.
But other analysts said Syria's overtaxed military was unlikely to retaliate and risk an Israeli onslaught that could tip the balance in its fight against the 22-month Syrian uprising. They also said Syria's ally Hezbollah was loath to provoke conflict with Israel as it seeks to maintain domestic calm in neighboring Lebanon.
Syria's ambassador to Lebanon declared that Syria "has the option and the capacity to surprise in retaliation." The Iranian deputy foreign minister warned that the attack would have "grave consequences for Tel Aviv." The Russian Foreign Ministry said the strike "blatantly violates the United Nations Charter and is unacceptable and unjustified, whatever its motives." Lebanon's Foreign Ministry also condemned the attack -- as did some Syrian rebels, seeking to deny Syrian President Bashar Assad a chance to rally support as a victim of Israel.
Many questions swirled about the target, motivations and repercussions of the Israeli attack, which Arab and Israeli analysts said showed the rapid changes in the region's strategic picture as Mr. Assad's government weakens -- including the possibility that Hezbollah, Syria or both were moving arms to Lebanon, believing that they would be more secure there than with Syria's beleaguered military, which faces intense attacks by rebels on major weapons installations.
U.S. officials said Israel hit a convoy before dawn Wednesday that was ferrying sophisticated SA-17 antiaircraft missiles to Lebanon. The Syrians and their allies said the target was a research facility in the Damascus suburb of Jamraya.
It remained unclear Thursday whether there was one strike or two. Also unclear was the research outpost's possible role in weapons production or storage for Syria or Hezbollah, the militant Lebanese Shiite organization that has long battled with Israel and plays a leading role in the Lebanese government.
The Jamraya facility, several miles west of Damascus, produces both conventional and chemical weapons, said Maj. Gen. Adnan Salo, a former head of the Syrian army's chemical arms unit, who defected and is now in Turkey.
Hezbollah indirectly confirmed its military function in condemning the attack on Arab and Muslim "military and technological capabilities." That raised the possibility that Israel targeted weapons manufacturing or development, in an attack reminiscent of its 2007 assault on a Syrian nuclear reactor, a strike that Israeli never acknowledged.
But military analysts said the jets' flight pattern strongly suggested a moving target, possibly a convoy near the center, and that the Syrian government might have claimed the center was a target to garner sympathy. Hitting a convoy made more sense, they said, particularly if Israel believed Hezbollah stood to acquire "game-changing" arms, including antiaircraft weapons.
Israeli leaders declared days before the strike that any transfer of Syria's extensive cache of sophisticated conventional or chemical weapons was a "red line" that would prompt action.