Syria’s claims that Israeli aircraft violated its airspace under the cover of darkness near the Turkish border, then were confronted by Syrian defense systems, dropped some objects on the ground, and left in a hurry have left numerous unanswered questions in their wake. A rare and thundering Israeli silence has compounded the mystery.

What did really happen on Thursday? Who else was involved? International terrorism? Russia? Iran? North Korea? America? Turkey? Syria supplied few details, and Israel none at all. There are 8 million theories in the naked cities of the Middle East.

Israel has often flown over Syria in the past, including over President al-Assad’s private residences. Did the Syrians finally acquire the means to respond? If so, why did they fail to down the aircraft? Mr. Assad’s deputy, Farouk al-Sharaa, threatened a “series of responses” Saturday, but did the incident, assuming it actually occurred, fill the Syrian military with confidence that it is finally ready for war with Israel?

And if by a response Syria’s upper echelons merely meant ratcheting up international indignation over Israel’s “aggression,” why did it fail until last night even to ask that the U.N. Security Council be convened? Was Damascus’s patron, Moscow, concerned that such a request would lead to questions about recent Georgian allegations that Russian planes violated Georgia’s airspace? Unlike the Syrian claims, incidentally, the Georgian allegations were backed up by radar data.

• And, speaking of Russia, was it involved in Thursday’s event? Israel has long accused Moscow of supplying missiles and anti-aircraft technology to Syria, some of which found its way to Hezbollah and was used in last year’s Lebanon war. Last week, Israeli officials said that earlier in the summer Moscow leaked bogus intelligence to Damascus about Israeli preparations for war. Russia also is reportedly building a home port for its Mediterranean-based fleet in northern Syria, where the alleged incident took place last week.

Did Israel fly over the beefed up Russian naval base in northern Syria for a quick look-see? Were Russian-made air defenses or even Russian troops deployed there involved in the shooting?

A 10-day-old Wall Street Journal op-ed piece by a former American ambassador to the United Nations, John Bolton, was widely recycled in the Israeli press over the weekend. “We know that both Iran and Syria have long cooperated with North Korea on ballistic missile programs, and the prospect of cooperation on nuclear matters is not far-fetched,” Mr. Bolton wrote. I am told Mr. Bolton has long tried to focus attention on North Korea’s ties to Syria, Iran, and Cuba, and that he has met with a lot of resistance in Washington.

Did the Israeli incursion expose any new North Korean information?

Or could the Israelis have targeted Syrian-based terrorists?

Also, Israel has long been suspected of plotting to destroy the nuclear facilities of Iran, a Syrian ally. Could the aircraft have mapped out an aerial route to Iran? And if so — and as Mr. Sharaa and other Syrian spokesmen have targeted the Bush administration in their rhetoric as much as they have Israel — was America involved in any way?

“Soon, the real story will probably emerge,” an Israeli friend with close ties to Prime Minister Olmert and other top Israeli officials told me yesterday, asking that his name not be used. “Right now, everybody — Israel, Syria, and anyone else who might be involved — has an interest in keeping things under wraps. They all have things to hide.”

Beyond the initial complaint and vague threats of an unspecified response at some point, my friend noted, Damascus has supplied no detailed account of the incident. No aircraft remnants allegedly left behind on Syrian soil have been put on display. No radar or satellite data were released.

Rather than responding, meanwhile, Mr. Olmert has toyed with the Israeli press. After telling reporters, “I don’t know what you are talking about,” he was videotaped greeting military generals at a pre-Jewish New Year reception with smiles that suggested high fives all around. Whatever happened that the pictures telegraphed, it was a great success. Uncharacteristically, there were no press leaks from eager army and intelligence sources, or from even more eager politicians.

Syria is not likely to respond militarily, one of my sources told me yesterday. After this, he said confidently, Mr. Assad is not likely to rehabilitate his image in Washington or anywhere else in the West. Naturally, he declined to say what “this” was.