Michael Walzer--a political science professor at Princeton University and author of the book Just and Unjust Wars--has an article out in The New Republic where he discusses the ethics of the war Israel is currently waging in Lebanon. Walzer is exceptionally clear on the core principle that there can never be attacks on civilian targets and that this also argues against some of Israel's attacks on the economic infrastructure of Lebanon and Gaza. That said, he also makes the following points:
I was recently asked to sign a condemnation of the Israeli operation in Gaza--a statement claiming that the rocket attacks and the military raid that led to the capture of Gilad Shalit are simply the inevitable consequences of the Israeli occupation: There "never will be peace or security until the occupation ends." In the past, I am sure, some Palestinian attacks were motivated by the experience of occupation. But that isn't true today. Hamas is attacking after the Israelis departed Gaza and after the formation of a government that is (or was until the attacks) committed to a large withdrawal from the West Bank. Similarly, Hezbollah's attacks came after the Israeli withdrawal from southern Lebanon. The aim of these militants is not to create a Palestinian state alongside Israel; it is to destroy Israel. Admittedly, that is a long-term aim that derives from a religious view of history. Secularists and pragmatists have a lot of trouble acknowledging such a view, let alone understanding it.
By contrast, the Israeli response has only a short-term aim: to stop the attacks across its borders. Until that is achieved, no Israeli government is going to move forward with another withdrawal. In fact, it is probably true that the Hamas and Hezbollah attacks have made any future unilateral withdrawals impossible. Israel needs a partner on the other side who is, first of all, capable of maintaining security on the new border and who is, second, actually willing to do that. I can't pretend that the Israeli military operations now in progress are going to produce a partner like that. At best, the army and air force will weaken the capacity of Hamas and Hezbollah to attack Israel; they won't alter their resolve. It will probably take the international community--the United States, Europe, the United Nations, some Arab states--to bring the Lebanese army into the south of the country and make it an effective force once it is there. And it will take a similar coalition to sponsor and support a Palestinian government that is committed to two states with one permanent and peaceful border and that is prepared to repress the religious militants who oppose that commitment. Until there is an effective Lebanese army and a Palestinian government that believes in co-existence, Israel is entitled to act, within the dialectical limits, on its own behalf.