astroprof has a succinct semi-technical summary on the hardware raining down on north Israel
my 2c worth...
What Hezbollah did was an act of war, a breach of truce, a violation of agreements; it was not, in this instance (the ambush of an IDF patrol), an act of terrorism. Hezbollah has committed acts of terror, in this case they committed an act of war; they've trapped Israel in a moral reverse.
Israel had the right to respond, and they do have the right to insist Lebanon control its sovereign soil and preclude third parties, or Lebanese government factions, from attacking its soil.
From the outside, it seems imprudent for them to insist on this right at this point. There were internal reasons, and they are also playing their own game to stir things up.
I guess we'll find out the hard way.