If we know anything about modern day Israel, it is that they hate elements of risk, even though they be slight. If this were not true, Hizbollah would have been eradicated long ago, and Hamas would suffer daily setbacks. As it is, Israel suffered only about 120 IDF casualties in the 2006 war and was ready to call it quits even though they had achieved none of their objectives. Any war calling for the invasion of Lebanon or the bombing of Iran will insure that Israel takes a lot more casualties than that. A lot more.
Gunmen kill 1, wound 13 at Sri Lanka election campaign (AP)
from the article: Iran official: We have obtained the S-300 missile system