For many years it has been the custom in Israel, on the eve of Rosh Hashana, the Jewish New Year, for the prime minister to grant interviews to the country’s three major newspapers and three main television channels. This has been Israel’s closest thing to an annual “state of the union” address.

And so when, over a week ago, Prime Minister Olmert’s office announced that Mr. Olmert was dispensing with this custom this year, eyebrows were raised. Mr. Olmert, the country was told, was too busy. Presumably, the prime ministers before him had all agreed to holiday interviews because they had nothing better to do with their time.

At first it was widely speculated that the prime minister’s decision came from not wanting to answer what he knew would be probing questions about the financial improprieties for which he is now under police investigation, or about the details of his current peace talks with Palestinian Authority president Mahmoud Abbas. Then came the mysterious incident of the night of September 6, on which Israeli warplanes, according to an official Syrian announcement, penetrated deep into northern Syria, were heard by local residents, and were driven off by ground fire. Israel’s uncharacteristic reaction to the Syrian report was to abstain from all comment. Was Mr. Olmert’s refusal to be interviewed also based on his knowledge that he would be questioned about this incident?

Perhaps — although had he been asked about it, of course, the prime minister could simply have added his “no comment” to the others. In any case, since September 6 the mystery has only deepened. What exactly were the Israeli aircraft (whose jettisoned fuel and ordinance tanks were found on both side of the Syrian-Turkish frontier some 200 miles from Syria’s Mediterranean coast, the apparent point of penetration) up to?

Were they on a reconnaissance mission? Testing Syrian air defenses? Deliberately signaling the Syrians how vulnerable these defenses were? Letting Iran know that Israeli planes could reach it via Syrian airspace? Attacking a secret Syrian installation?

None of these possible explanations, it must be said, entirely makes sense. Reconnaissance missions are generally carried out during daytime and at altitudes from which they cannot be heard on the ground. Syrian air defenses, one would think, would interest Israel most in areas close to a possible Israeli-Syrian military confrontation, not hundreds of miles away along the Turkish border.

And if these defenses are vulnerable, why inform the Syrians that Israel knows this and so give them a chance to correct their deficiencies? The same holds true for Iran: If Israel has a contingency plan to bomb its nuclear facilities via Syria, why let it know now?

An attack on a Syrian installation, then? This likelihood was hinted at several days after the incident by Syrian parliamentarian Mohammed Habash, who often acts as a spokesman for the Syrian regime. Comparing Israel’s action to its successful 1981 air strike against Iraq’s Osiris reactor, Mr. Habash claimed that this time it was a “disappointment and failure.”

Yet what secret Syrian installation could we be talking about? And if there was one, why didn’t the same local residents who reported hearing planes in the air also report hearing explosions on the ground? And if the attack failed, why did Israel’s top brass and Prime Minister Olmert seem so jauntily satisfied with themselves in the days after it? And if it succeeded and Mr. Habash was trying to deny it, why should Syrian television have raised the subject at all when Israel was keeping it under wraps?

Moreover, there is another puzzle here. All summer long Israel, fearful of a possible “miscalculation” in regard to Israeli intentions on Syria’s part that might lead to a military clash, has sent the Syrians calming reassurances that they had nothing to worry about.

What would be the point of doing all that and then staging a surprise attack on a Syrian military facility? What better way could there be of convincing the Syrians that Israel is really preparing for war and that they would be wise to strike first?

Sooner or later, the truth about what happened on the night of September 6 will come out: It may take months or years for it to do so, and it may take weeks or only days. One can only hope that when it does, Israel will have nothing to be embarrassed about and that its military and political judgment will not once again look as bad as it did at the end of last summer’s war in Lebanon. Beyond that, there is the question of Mr. Olmert’s canceled interviews. They do not make a good impression. In a country where the prime minister rarely holds press conferences, Israelis have traditionally relied on these interviews to give them an indication of what their leaders are thinking and where they are planning to take their country.

This is something they deserve to know, just as they deserve to know, if only in a general way that gives away no military secrets, what their country’s airplanes were doing in the skies of Syria last week.

Prime Minister Olmert, whose approval ratings have long been in single digits, is showing considerable contempt for the Israeli public by behaving in this fashion. No doubt he believes that, between this Rosh Hashanah and the next, he will chalk up enough successes to make being interviewed worth his while. And if he doesn’t, he won’t be around a year from now to be interviewed anyway.

Mr. Halkin is a contributing editor of The New York Sun.