JERUSALEM (Reuters) - Any sign of Syria's grip on its suspected chemical weapons slipping as it battles an armed uprising could trigger Israeli military strikes, Israel's vice premier said on Sunday.
Silvan Shalom confirmed a media report that Prime Minister Benjamin Netanyahu had last week convened security chiefs to discuss the civil war in nearby Syria and the state of the country's chemical arsenal.
The meeting, held on Wednesday, had not been publicly announced and was seen as especially unusual as it came while votes were still being counted from Israel's national election the day before, which Netanyahu's party list won narrowly.
Should Lebanon's Hezbollah guerrillas or rebels battling forces loyal to Syrian President Bashar al-Assad obtain Syrian chemical weapons, Shalom told Israel's Army Radio, "it would dramatically change the capabilities of those organisations".
Such a development would be "a crossing of all red lines that would require a different approach, including even preventive operations", he said - alluding to military intervention, for which Israeli generals have said plans have been readied.
"The concept, in principle, is that this (chemical weapons transfer) must not happen," Shalom said. "The moment we begin to understand that such a thing is liable to happen, we will have to make decisions."
Interviewed separately by Army Radio, Civil Defence Minister Avi Dichter said Syria was "on the verge of collapse".
But asked whether Israel perceived an imminent threat, Dichter said: "No, not yet. I suppose that when things pose a danger to us, the State of Israel will know about it."
France, among the most vocal backers of Syria's rebels, said last week there were no signs Assad was about to be overthrown since international mediation and crisis diplomacy were going nowhere. The conflict also appears largely stalemated on the ground.
Syria has loomed large in Israeli rhetoric in recent weeks.
"The great danger to the world is ... from nuclear weapons in Iran, those weapons that are built in Iran. It's chemical weapons in Syria falling into the wrong hands," Netanyahu said in a January 7 speech.
Two days later, Dichter told Israel Radio that monitoring Syria was "the top priority - that is, a very high priority".
An Israeli government security adviser told Reuters on Sunday that Syria had taken new prominence in strategic planning "because of the imminence of the threat. There the WMDs (weapons of mass destruction) are ready and could be turned against us at short notice."
Raising the regional stakes, Tehran, among Assad's few allies and itself long the subject of Israeli war threats over its nuclear programme, said on Saturday it would deem any attack on Syria an attack on Iran.
Israel and NATO countries say Syria has stocks of various chemical warfare agents at four sites. Syria is cagey about whether it has such arms but insists that, if it had, it would keep them secure and use them only to fend off foreign attack.
Syria is widely believed to have built up the arsenal to offset Israel's reputed nuclear weapons, among other reasons.
Netanyahu had sought to burnish his hawkish credentials ahead of the ballot, in which centrist rival made big gains.
The government adviser, who spoke on condition of anonymity, said Netanyahu might have a secondary interest in playing up security threats given that his rightist Likud-Beiteinu party list suffered surprise election setbacks and must now seek a new coalition with a constellation of political challengers.
"But Syria is a serious business, and the people dealing with it in Israel are serious," the adviser said.
Israel's biggest-selling newspaper Yedioth Ahronoth on December 28 quoted the deputy armed forces commander, Major-General Yair Naveh, saying that weapons developed for a possible strike on Iran could have "usefulness for other confrontations in our vicinity, including in Lebanon and Syria".
Writing by Dan Williams; Editing by Jeffrey Heller and Mark Heinrich