The Hezballah dilemma
For years, the radical Shia movement has painstakingly amassed an arsenal of Iranian-supplied weaponry. Today, Hizbollah has tens of thousands of missiles carefully stockpiled in south Lebanon and readied for use against Israel.
If Hassan Nasrallah, the Hizbollah leader and a man who once basked in the adoration of the Arab world, is not prepared to launch his deadly armoury now, then when might he ever do so? He must decide whether to retaliate for the air strikes by bombarding Israel - and almost certainly starting a regional war - or sitting tight and risking the appearance of a paper tiger.
Israel clearly believes that Mr Nasrallah will choose caution. Benjamin Netanyahu, the Israeli prime minister, authorised the raids on Syria and then nonchalantly flew to China on a visit that will keep him away until Friday. This was not the behaviour of a leader who believes his country to be on the brink of war.
Israel has moved two of its five Iron Dome missile defence batteries near the border with Lebanon. But General Yair Golan, the head of Israeli Northern Command, told journalists that he did not sense any "winds of war". He spoke while joining the annual fun run for the Golani Brigade - again, hardly the behaviour of a general who thinks he is about to fight.
Instead, Israel senses the prospect of a strategic victory over Hizbollah. Mr Nasrallah faces his dilemma at a uniquely testing moment.
Hizbollah gets its weapons from Iran, but they must reach Lebanon across Syrian territory. If President Bashar al-Assad goes, so might this vital supply route.
The leaders of post-Assad Syria will almost certainly be drawn from the country's Sunni majority, who are not natural allies of Shia Hizbollah, and still less of Iran.
The fact that Mr Nasrallah has sent his men to Syria to fight alongside the current regime almost guarantees him the enmity of any future ruler.
The possible loss of his supply line will alter Mr Nasrallah's calculations.
When he started the last war with Israel in 2006, he knew that every missile he fired could be replaced by Iran - as indeed they were. This time, there might be no new supply of rockets down the road from Syria.
...The likely response maybe to attack Israeli tourist in some other country. That is not likely to solve his dilemma with Israel. I so suspect that Iran would try to supply Hezballah by sea if they lose the Syrian airspace. Syria really has no good alternatives for dealing with Israel. Their army has been to depleted by the rebels. Israel could have its tanks patrolling the streets of Damascus in a very short period of time.