Iron Dome - success overstated?

Now the dust has settled on last year's Gaza punch-up, Professor Ted Postel of MIT has been looking at Iron Dome's performance. He's not particularly impressed:

According to Dr. Pedatzur, American expert Professor Theodore A. Postol said, "If the definition of a successful interception by the Iron Dome means destroying the warhead of the attacking missile, then the rate of its success during the Pillar of Cloud operation is very low: probably 5%."

He raises an interesting question: what is a successful interception by Iron Dome? Remember that a substantial component of Iron Dome is its knowledge of vulnerable versus safe areas for missiles to land in; it therefore engages a small subset of the ballistic missiles actually fired at it. Postol is pointing out that the warhead of a Qassam (a stovepipe with high explosive in the nose and fins welded on the back) is not huge and actually quite tricky to destroy.

If we can't judge success by the bangs in the sky, can we judge by the damage on the ground?

"Israelis have submitted about 3,200 requests to the authorities to repair homes that have been damaged by Palestinian rockets", which appears to be excessive given the IDF's claim that only 58 rockets got past Iron Dome.

Hmm. I'm not so sure about this. It depends very heavily on what "damage" consists of. I can well believe that even a small warhead, 5 to 10Kg of HE for the smaller Qassams, going off in an urban setting could mess up the windows of 10-20 houses and thus occasion a claim. That's before any fraudulent claims. So 58 rockets could conceivably generate 1000 claims; certainly, the numbers suggest more rockets landing than claimed, but it still looks like a healthy interception rate. That Rafael Armaments and the IDF are putting the best possible shine on Iron Dome's performance doesn't surprise me.

What's interesting is that Ted Postel was quoted back in November 2012 being fairly positive about Iron Dome:

"How well did Iron Dome work?"
It appeared to work very well—a lot better even than the people involved in building it expected. It's an astonishing achievement—I think it's even fair to use the word miraculous—to be able to hit these rockets with the reliability they demonstrated.
...
There were some news reports where they were talking about saving hundreds of lives, but that's a total misunderstanding of the lethality of these weapons. Before the recent attacks, some 11,000 or 12,000 rockets and mortars were launched over six or eight years, and in total, 60 or 61 people were killed. So if you are saving lives, it would be "several" lives.

It's therefore not obvious that Postel has an interest in playing down Iron Dome's performance, and he's had time and opportunity to review more data on it. I am not sure that the data he quotes fully supports his claims, but without much more detailed analysis it's hard for either of us to be sure of the real story.

The most important thing Iron Dome did, of course, was to make Israeli citizens feel relatively safe from Qassam rockets. It therefore provided political cover for the prosecution of the Israeli offensive against Hamas and their friends, which probably had a far greater medium and long term utility for Israel than keeping rockets out of homes.