This (brief) diary will address what I believe to be Israel's strategic purpose in launching the current round of attacks.
Its my central thesis that Israel has launched this round of attacks to end the problems of fighting an asymetrical war on its northern front. I believe further that the plan will likely work.
I am not addressing the morality of this war. I'm merely offering my opinion about Israel's motivations.
The Israeli strategy was laid out, actually, over two decades ago in a book called THE GRAND STRATEGY OF THE ROMAN EMPIRE, by a former Israeli general. Its theme, when distilled, basically comes down to this:
(1) The Roman Empire arose when its forces -- better trained, better armed, and better fed -- faced defined armies rather than irregular forces. Its strategy was simple: conquer what it needed to, but then, through diplomacy, create a buffer of client states around it to absorb the attacks of outside tribes. Where it had the most problem was along the German border, were it had a porous and long front.
(2) The threat to Rome changed, and Roman strategy changed. Rome eventually incorporated client states until it could incorporate no more -- and eventually, the roman border proved to be directly abutting strong enemies with centralized forces. Rome then adopted a strong perimeter defense with an ability to project force outwards -- but, in time, the price became too high.
(3) The threat then changed again, to a massive shift of low-intensity raids coming over the borders. These low intensity raids made it impossible to have much in the way of commerce or culture in Europe, with the result that it became ever-more-difficult to protect the empire. In the east, where the threat of these incursions could be minimized and controlled, the Empire continued on. In the West, where these incursions could never be controlled, the Empire became little moe than an armed camp -- the beginnings of feudalism and the end of Rome.
(4) Finally, with its economic base in ruins, Roman Europe essentially became a battle-zone, with little ability to support the legions in the way of the past. And so, over time, when the fighting strength of the legions declined, there eventually arose serious armies who could challenge the Roman forces. These new forces -- often armed with technology and tactics borrowed from the Romans themselves, eventually overwhelmed the West.
The Israeli position is, in fact, quite similar to Rome in some ways. It no longer has client states around it that are cowed; in Lebanon, its border is absolutely abutting territory of its enemies, who constantly launch low-level incursions against it. Unwilling to concede territory, Israel now has decided to launch what might be called a limited forward defense -- that is, projecting its force from its borders approximately 25 miles into Lebanon.
What Israel will do, I expect, is level this 25 mile border, and then place artilery and rockets on that flank. It will bomb -- and will continue to bomb -- that area after its troops withdraw, creating essentially a moat of fire in which no one will live. Essentially, it will make a DMZ like that in Korea.
Israel predicts (I suspect) that it will face UN calls to pull its troops out of Lebanon immediately after the invasion. Israel expects that it will do so, but it will do so after leveling everything along that border, so that its "moat" will be well protected. This is the reason that Israel has dropped its leaflets, telling the inhabitants of South Lebanon that it is about to declare a free-fire zone. It wants everyone on notice that those who stay behind will be targets.
There is a certain rudimentary sense to this action. With a 25-mile Israeli bombardment zone, it will be exceptionally difficult for Hezbollah to launch missile attacks on Israel or cross-border raids. Unlike a formal occupation, Israeli troops won't be stationed permanently inside Lebanon -- so there will be few opportunities for Hezbollah to retailiate against Israel directly in the disputed territory. And Israel has been bombing Lebabon for decades -- the usual rule is that when bombs drop, the UN complains, but does nothing.
The grand strategy in the Israeli north thus appears to be to build a meaningful divide between Israeli and Arab forces. This is paralleled in the Israeli "Security Buffer" / Fence / Wall / Fortification, which is designed to keep Palestine's inhabitants out of Israel and themselves separated.
There appear to be two potential flaws, or perhaps three, with the Israeli calculation. The first is whether the conflict spreads to Jordan, either directly (the Hashemites end up getting replaced by a more anti-Israel regime) or indirectly (Hamas and Hezbollah begin using the Jordanian border as a springboard to launch the same sort of attacks as have been launched from Southern Lebanon. If this did so, Israel would have a much longer border to defend, and it may make it difficult to dig a "moat of fire" along that front.
A second potential flaw is that Israel, for all that it beats on the Palestineans, still uses the Palestineans as cheap labor. This means that the very people it fears will bomb Israel have access to Israel on a daily basis. This looks a lot like apartheid, and, while apartheid may work for a while, historically it does not work forever.