As we know, Israel wants Hezbollah off Lebanon's southern border so that the rocket attacks on its civilians will end. The Lebanese government was supposed to disarm Hezbollah over the past few years and deploy its own army on the border, but it's been much too weak to do so, and has been reluctant to confront Hezbollah for fear of triggering another civil war. (Nor, for that matter, has the Lebanese government received much help from the international community towards this end, despite the fact that UN Security Council Resolution 1559 explicitly calls for the disarmament of Hezbollah.)
So that's where things get tricky. Besides being immoral, Israel's current strategybombing lots of suburbs and killing a bunch of civiliansdoesn't appear likely to achieve its goals. If the IDF couldn't eradicate Hezbollah during its occupation of southern Lebanon from 1982 to 2000, it's unlikely to do so now. And it seems especially unlikely to do so by turning northern Lebanon into rubble, which will only weaken the Lebanese government vis-à-vis Hezbollah.
But what else can be done? Kofi Annan and Tony Blair are calling for an international peacekeeping force to enter Lebanon, and quell the fighting. But what then? It's not even clear that an international force could disarm Hezbollah, as Israel seems to desire (simply moving the militiaand its long-range missilesaway from the border won't put an end to the underlying issue here). The U.S. can't even disarm Shiite militias in Iraq and it has over 100,000 troops there. Hezbollah is still very popular among Shiites in Lebanon's south. This seems like the sort of thing that ought to be tried, at least, but it's also possible that this entire mess really is as intractable as it seems.