Is the attack on Lebanon "proportional" to the damage, or the threat of damage, to Israel? Is it "justified" before God, or international law, or history, or anything? And just what are "roots" of the Israeli-Arab conflict? Hezbollah's capture of two Israeli soldiers, as Condoleeza Rice has proclaimed? Or something much deeper, much older, like, for example the Balfour Declaration of 1917, or any of the many offenses Arabs, Israelis and their respective allies have committed against each other in the decades since? Or something even older?
Whatever my opinion, it's not going to persuade you. People remain very unpersuadable on questions framed this way. But if you want to read some opinions, here are a bunch: "public opinion" Israel Lebanon - Google News
But these are the wrong questions. Whether the attack is "proportional" depends on the question, for what ends? And whether it is "justified" can only be answered, not in terms of holy scripture or revelation, or even history, but its known or likely consequences.
I agree with that great philosopher of pragmatism Leon Trotsky, who argued that the problem was not whether the ends justify your means; the problem is to justify your ends. 1936: Their Morals and Ours. Let's look at Israeli ends and means.
Ehud Olmert said at first that his aim was to secure the release of three soldiers, one seized by Hamas and two by Hezbollah. That sounds absurd, because an air attack (in Lebanon) and tank assault (in Gaza) seem like the least likely ways to achieve it. Olmert is new at this governing business, but he can't be such a fool as that.
The second, more plausible announced aim is destroying Hezbollah's central command and its capacity to fire rockets into Israel. This I believe. But if so, it raises two further questions:
First, is this bombing campaign an effective means to that end? Maybe, but only for a time. But if Hezbollah is the target, the main victims are the Lebanese whom Israel officially regards as innocent. Even if all the present leadership of Hezbollah were killed, don't you think some other group, with or without the same name, would arise to avenge them?
Second and much more importantly, why such a puny goal? A lull in the attacks from Lebanon, rather than a permanent peace? And at such expense in terms of Israel's long-range security. Compare this to the visions that many other Israelis have had of Israel's future: a country with respectful, if often tense, relations with neighboring states and with its own growing Arab minority. Trade relations would strengthen other ties, and extending further rights to Palestinians with the opportunities to lead productive lives would (it was expected) evaporate much of the hostility and be beneficial to both parties. Among those with such a vision was a famous general: Yitzhak Rabin
The Israeli offensive is not getting at "the root cause," because there are always deeper roots. It is not making Israelis safer in the short run -- scores have already been killed in what Hezbollah describes as reprisal missile attacks. And it certainly isn't going to make them safer in the long run. Yes, Israel must defend itself because it has enemies who want to destroy it utterly. But this response to its enemies is increasing their passion and their number.
And not to mention the agony of Lebanon and the continued punishment of the Gazans.