The secret is out. But the speculation has not ended. And the tension lingers dangerously.

Israel has suddenly broken its exceptional news blackout on a covert air raid against Syria, admitting officially its warplanes hit a "military installation" on 6 September.

This unexpected disclosure, after weeks of mysterious silence, came hours after the first public comments from Syria's President Bashar al-Assad.

He ended his silence in a BBC interview, saying Israeli jets hit "a building under construction related to the military but it's not used, it's under construction so there's no people in it, there's no army, there's nothing in it".

So now it is official, on both sides. But speculation over exactly what was hit continues to create ripples in capitals around the world.

Was it a suspected nuclear site established with North Korean help? Had Pyongang tried to dispose of some nuclear material to evade the inspectors? Maybe it was a Hezbollah arms cache? Or perhaps a test of Syria's new air defences?

'Propaganda'

Why, I asked the president, would Israel carry out such a high-risk raid if it was not such a high-value target?

President Assad just batted the incongruity away. And, as always in the Middle East, history provided the answers.

"The propaganda reminds us," he said, "of what happened before the war in Iraq when they showed all the concrete evidence that Iraq had nuclear weapons or weapons of mass destruction which turned out not to have existed at all."

But Israel clearly sent a message to Damascus. Did Damascus get it?

The fact President Assad decided to give a rare interview suggested he had a message or two he also wanted to pass on.

What did Israel's raid tell him? That Israel had "a fundamental, visceral antipathy towards peace".

But Israel has also been sending messages to try to bring down the temperature.

Israeli Prime Minister Ehud Olmert even went so far recently as to offer a rare compliment to Mr Assad, saying "we have respect for the Syrian leader and the Syrian conduct".

President Assad seemed embarrassed by the personal praise.

Neither peace nor war

In his interview, he spoke of a time of "non-peace and non-war" in a region where it had to be "either peace or war... there is no third option".

And yet, despite his firm assertion that Syria reserved the right to retaliate, Mr Assad's responses underlined a recognition of the dangers of military escalation.

"Retaliate doesn't mean missile for missile and bomb for bomb... this is the last option," he said.

One source in Damascus said Israel had made it absolutely clear its riposte to any Syrian strike would be "devastating".

But that has not stopped intense debate, in coffee shops and the corridors of power on both sides, about a possible strike by Syria or Israel - or an accidental war, a miscalculation when mistrust and misunderstanding run so deep.

Continuing strains

Ever since last year's punishing war in Lebanon both sides have spoken of their readiness for peace but they've also reinforced their defences along the occupied Golan Heights. Damascus wants this territory back as part of any peace deal.

Syria is known to have acquired better long-range missiles and upgraded its air defences with Russian and Iranian help.

So that leaves them in that sensitive "non-war, non-peace" situation.

Months ago, all talk was of a summer war or a return to the peace talks broken off in 2000.

But in June, US President George W Bush made it clear to Ehud Olmert that Israel did not need Washington's approval to talk to Damascus.

That, said Mr Assad, confirmed there was no point in talking.

"From our experience of 16 years of a peace process, the main factor is the US administration," he said.

Continuing strains between the US and Syria mean the Bush team has no interest in going down this track.

Incomplete picture

On an earlier trip to Damascus, as the blistering seasonal heat began to ease, I commented to a Syrian friend that the "summer war" had also not materialised.

"Oh," she answered, "but there could be an autumn war."

And then came the Israeli air strike.

So Mr Assad, like his father Hafez al-Assad, seems resigned to the "long game" because of what he calls "the realities".

He clearly feels he has his own cards to play, not least Syria's relationship with a range of militant Palestinian and other Arab groups including Hezbollah in Lebanon.

There are some signs Damascus has been trying to use its influence more positively to reduce tensions but not enough to please most of its critics.

"They can't isolate Syria," he insisted.

So this week, a few more pieces of this latest Middle East puzzle were put in place.

But as long as there are big black holes in this jigsaw, people will continue to fill them with their own pieces, whether or not they really fit. This means everyone will continue to see a different picture - and that is dangerous.