Israel wants to retain the "option" of attacking Iran at some point in the not too distant future. They cannot comfortably do this unless Hizbollah and Syria are "neutralized". It is widely accepted, as implied in this article, that Israel will manufacture a reason to start a war in which they will have a new opportunity to take on Hizbollah. In this war which is coming, Israel will plan to eradicate Hizbollah as best they can, even if the cost is very high. Israel will have intelligence on Syrian missile sites and will eradicate them as best they can. Only after this preparation will the option to attack Iran remain alive. On the other hand, if Israel attacks Syria, a war with Iran may come much sooner than Israel expects. The good news for the IAF is that if such a war starts, they will find out for sure where all those Russian made anti-aircraft systems are located although that knowledge will not come cheap.
Nigeria says troops destroy extremist camp, rescue 178 people (AP)
from the article: Israel's best intentions may not be enough to avert war in Lebanon