As in the past, the Holy See also condemns both the terrorist attacks on the one
side and the military reprisals on the other... [Israel's right to self-defense] does not exempt it from respecting the norms of international law, especially as regards the protection of civilian populations. In particular... The Holy See deplores the attack on Lebanon, a free and sovereign nation.
From Pope Benedict XVI:
There is nothing here that is incompatible with traditional just war theory. To review, the principles of just war ad bellum (reasons for the war are): just cause (usually interpreted as self-defense or defense of another); declared by proper authority; right intention; a reasonable chance of success; a last resort; end is proportional to the means. By my count, the Israeli action violated the last 4, especially proportionality. The tests for just war in bello (how the war is raged) are: discrimination (combatants versus civilians), and proportionality. Again, I think the response falls down here.
At the origin of these cruel oppositions there are, sadly, objective situations of violation of law and justice... But neither terrorist acts nor reprisals, especially when they entail tragic consequences for the civilian population, can be justified... By such paths, as bitter experience shows, positive results are not achieved.
And yet some American Catholics are up in arms about the Vatican response to the current crisis, testament to the fact that the cafeteria swings wide open on the right. I know she's an easy target, but Michelle Malkin represents the views of many on the Catholic right when she claims to be "incensed" by the Vatican's condemnation of Israel. These statements do not diverge from the church's approach to just war theory. But the Vatican is not going to buy the American line that Israel deserves full support, any more than it bought Michael Novak's attempt to persuade them that the invasion of Iraq was supported by just war theory in 2003.
What drives this American Catholic exceptionalism? Sadly, a lot of it comes from the influence of Calvinism, and its notion of predestination. Such a theology allows a person to divide the world into two groups-- the good/ saved and the evil/ damned. By this logic, it is perfectly fine to wipe out the evildoers, as they are damned anyway. Out the window goes just war theory! But by Catholic reasoning, it is never valid to assign collective guilt. Nor are there are "evil people", only people who do evil actions. But the principle of retribution rather than justice (the Old Testament lex talionis) looms large in American public debate, as witnessed by its continual support for the death penalty.
There is an even deeper problem, an attachment to a kind of consequentialist foreign policy, whereby the morality of an action depends on its consequences. The reasoning is clear: Hezbollah are terrorists, and a threat to Israel. Therefore, they can be destroyed by any means possible. Again, this kind of reasoning is the antithesis of Catholic reasoning. It is never licit to engage in an objectively immoral act, no matter what good might come out of it. To put it in simpler terms, the end does not justify the means. This has some stark implications. Noted Catholic philospoher G.E.M. Anscombe, well-known in conservative circles, launched a blistering attack on Harry Truman for dropping nuclear bombs on Hiroshima and Nagasaki-- she called him a war criminal and a mass murderer. Note that these bombings were defended by pure consequentialist logic: kill lots of Japanese civilians today to shorten the war, and save more lives (especially American) tomorrow. But I think few American would align themselves with the Anscombe camp. [Incidentally, the justifications for abortion also appeal to this kind of consequentialist reasoning, but very few on either the right or the left note the obvious parallels.] Applying this to the current day, I think there is a feeling among many that extraordinary measures are required to defeat Islamic terrorism, given the hideous tactics that these groups sometimes use, and the fact that they are not responsible to any clear public authority. This reasoning also lies behind the US use of torture, but that's a post for another day!