JERUSALEM: Military secrets are not readily divulged anywhere. But in Israel the blanket silence that envelops officials after an event like Wednesday's mysterious air strike on Syria reflects a deeper strategy involving both deterrence and outreach.

Beyond customary concern to safeguard spies and tactics for a government currently engaged in a graver confrontation with Iran, Israelis see such reticence as allowing their foes to save face and thus reduce the risk of reprisal and escalation.

Keeping silent, and so avoiding accusations of provocatively bragging of its exploits, also smoothes Israel's discreet cooperation with Muslim neighbours - such as Turkey or Jordan - who might otherwise feel bound to distance themselves.

Israeli leaders see benefit at home from not trumpeting successes that might give their public, or indeed Western allies, an exaggerated faith in their forces' capabilities.

And given international complaints that an unprovoked strike on a sovereign power breached international law, admitting the fact could only provide diplomatic complications.

So it was in 2007, when then prime minister Ehud Olmert muzzled his staff after the bombing of a suspected Syrian atomic reactor - a no-comment policy still in effect, though the United States has freely discussed that Israeli sortie and its target.

Olmert "wanted to avoid anything that might back Syria into a corner and force Assad to retaliate," the U.S. president at the time, George W. Bush, would recall in his memoir.

A former Olmert aide confirmed that account, telling Reuters the premier also feared for close military ties with Turkey, whose territory the Israeli warplanes crossed en route to Syria.

Israelis were then - as now - poised for a threatened war against arch-enemy Iran. Olmert, sceptical about whether Israel had the clout to take on the distant and much larger adversary, did not want to mislead his public by playing up the successful but far smaller-scale sortie against Syria next door.

"We knew the message of what had taken place would be received by the Syrian and Iranian leaderships, and that was enough for us," the ex-aide said on condition of anonymity.

So if Israel did attack a Syrian arms convoy headed to Lebanon's Hezbollah, or a military complex near Damascus, around dawn on Wednesday, as described by various sources, a similar logic may now be keeping Prime Minister Benjamin Netanyahu, his cabinet and defence chiefs quiet.

Tackling the Iranian nuclear programme is Israel's top priority, making it hesistant to lurch into other conflicts - especially with Syria's Assad government, an old enemy whose menace has faded, in Israeli eyes, with the two-year-old revolt.

Nor does Israel seek a flare-up with Hezbollah, which has mostly held fire since their 2006 war in southern Lebanon.

LINES AND ALLIES

Russia, Damascus's long-time arms supplier, said any Israeli air strike would amount to unacceptable military interference.

A former Israeli national security adviser, Giora Eiland, agreed. If Israel indeed attacked Syria, he said, eluding legal scrutiny might be a secondary reason for its silence: "The U.N. will never jump to back a military operation - certainly not by Israel," Eiland told Reuters.

Mindful, perhaps, of the self-imposed silence that would follow any raid, Israeli officials may have taken pains to offer justifications for any intervention in advance.

For months, they had been saying that if Iranian-backed Hezbollah, or Syria's Islamist rebels, acquired Syrian chemical weapons or advanced Russian missiles as Assad's grip faltered, that could pose a new order of threat to Israel - a "red line" the Netanyahu government said must not be crossed.

Such warnings came thick and fast early this week, then died out when news surfaced of Wednesday's strike - albeit some hours after it took place, a lag itself attesting to Israeli stealth and, perhaps, Syrian and Lebanese reluctance to go public.

Israel's military censors then quickly stepped in, barring media there from reporting anything on it from Israeli sources.

For Israeli media to have given even anonymous commentaries on an attack on Syria from Israeli officials, would only make it harder for the Israeli government to avoid provoking hostility from Turkey, Saudi Arabia and others on whom it is counting for at least quiescence in its struggle with mutual foe Tehran.

The former Olmert aide said Israel's secrecy policy amounted to "recognising Middle East manliness" - not adding insult to injury for enemies and friends alike. Control of its own media by the censors reflected the fact that, "in this part of the world, many people see the messaging from a country's media as synonymous with the messaging from that country's government".

So whether Israel wants to avoid provoking Syria, Hezbollah and Iran, or alienating Turkey and the Sunni Arabs, the former aide said, "silence is the best way forward".