Maybe Because... It's a war

Things like this make me a bit crazy.

Destroying the Beirut airport, blasting communications towers into oblivion and cleansing southern Lebanon of its civilian population are not measures the world will see as an attack on Hezbollah terrorists.

The "world" doesn't see anything that Israel does as an attack on terrorists. Israel is not a wee small nation surrounded by people who want to destroy it, it's a big giant bully terrorizing all it's neighbors, according to the "world."
Reality. The airport is a good target when fighting a war because that's where extra arms & ammunition & reinforcements are going to come from, same thing with the bridges & roads. Communication towers, now why on earth would you want to disrupt communication during a war? Oh, maybe in order to keep they enemy off balance & unable to quickly respond to your initiatives. "Celansing southern Lebanon of its civilian population" I'm assuming means chasing everyone out unless this is a statement that Israel is taking part in ethnic cleansing, of which I'd want proof. So, they're chasing away the civilians instead of killing them? And that's bad? Color me confused.

Hezbollah's stature in the Arab world is growing

Even as its membership is shrinking.

which should lead them to question whether a few weeks of bombing will do the trick.

No. Which is why they are invading & bulldozing terrorist bunkers & strongholds. They're cleaning the terrorists out of the area and will withdraw, because they have learned their lesson in regards to occupation and clearly want none of it. Still, I wouldn't call it scortched earth unless they're also burning crops & poisoning wells, etc.. See, words have meaning & scortched earth, as a military policy, has methods, few of which seem to be at play here.
Anyway, luckily, right in the same paper (the NYT might try balanced opinion pieces some time) is a different point of view. Further, we get it in language that I understand:

It is necessary to reestablish deterrence: You slap me, I will punch out your lights.

And kick you in the groin & blow out a knee & pop a few ribs... That's all assuming you don't try to fight back. I like Israel's approach. It is appropriate. They didn't start this fight, but they are sure as hell going to end it (at least this battle).

Gaza, too, was a retreat. There are many ways to mask it but no way to change the reality. The government of then-Prime Minister Ariel Sharon concluded that Israel was incapable of controlling a densely populated area full of people who hated the occupation. Israel will in due course reach the same conclusion when it comes to the West Bank, although the present war has almost certainly set back that timetable. The fact remains that for Israel to survive, it must withdraw to boundaries that are easily defensible and hard to breach.

It's clear now that those boundaries -- a wall, a fence, a whatever -- are immaterial when it comes to missiles. Hezbollah, with the aid of Iran and Syria, has shown that it is no longer necessary to send a dazed suicide bomber over the border -- all that is needed is the requisite amount of thrust and a warhead. That being the case, it's either stupid or mean for anyone to call for proportionality. The only way to ensure that babies don't die in their cribs and old people in the streets is to make the Lebanese or the Palestinians understand that if they, no matter how reluctantly, host those rockets, they will pay a very, very steep price.

Absolute truth. It's the only right answer. Why is this so hard for people to fathom?
He finishes with:

These calls for proportionality rankle. They fall on my ears not as genteel expressions of fairness, some ditsy Marquess of Queensberry idea of war, but as ugly sentiments pregnant with antipathy toward the only democratic state in the Middle East. After the Holocaust, after 1,000 years of mayhem and murder, the only proportionality that counts is zero for zero. If Israel's enemies want that, they can have it in a moment.

Again, complete agreement.