Israeli Success in Downing Hamas Rockets Has World’s Attention

But even ardent supporters of a continent-size missile shield to guard the United States and other NATO members acknowledge the limitations of Iron Dome, which is a tactical system designed to shoot down unsophisticated rockets — basically flying pipe bombs — with a range of less than 50 miles.

Some American technical experts also say they want hard evidence before judging whether Iron Dome knocked out as many rockets as Israel has claimed. Iron Dome’s most salient feature, according to American experts now examining after-action reports from Gaza, may well be its software: The system rapidly discriminates between incoming rockets that are hurtling toward a populated area and others not worth expending a far costlier Iron Dome interceptor to knock down.

The conflict between Israel and Hamas focused global attention on missile defenses, and came as the United States and its Arab allies have undertaken a costly effort to knit together a regional shield in the Persian Gulf to protect cities, oil refineries, pipelines and military bases from a potential Iranian attack.

“This will ratify the common-sense notion that these systems can play a role in defending you,” said Eric S. Edelman, a former under secretary of defense for policy in the George W. Bush administration. “It will be especially relevant as we move into an era in which there will be more countries with small inventories of rockets and missiles — and more countries that will want to defend against them in a reasonable way.”

The effort in the gulf is envisioned to include advanced radar as well as sets of two antimissile systems with accompanying radar: Patriot Advanced Capability interceptors and the Terminal High Altitude Area Defense. Those weapons would be linked with the radars and missiles carried aboard American Aegis warships in nearby waters.

There is a similar effort in the Pacific centered on radars in Japan, Aegis warships at sea and land-based interceptors in Alaska and California.

The Obama administration’s more recent focus has been the system to protect NATO allies in Europe with advanced radars based in Turkey and long-range interceptors to be based first in Romania and subsequently in Poland. American officials have emphasized that the limited number of interceptors in Europe are all about Iran, and would be inadequate to blunt Russia’s vast nuclear arsenal; but the system remains an irritant in relations with Moscow.

During the conflict with Hamas, Israeli officials report that Iron Dome knocked down more than 400 rockets on flight paths to populated areas, with a kill rate of 85 percent. Hamas is said to have fired off more than 1,400 rockets in all, but Israel was able to limit Hamas’s ability to launch more of its arsenal of 12,000 rockets with pre-emptive attacks on the storehouses where they were kept.

But some antimissile experts have expressed doubt about Israeli claims for Iron Dome, which is built by Israeli defense firms but has received about $275 million in financial support from the United States. Bright flashes can create a visual impression of overwhelming interceptor success, when in fact they may represent nothing more than the interceptor warhead blowing up, these skeptics warn.

“I’ve met the guys in Israel, and they’re smart,” said Richard M. Lloyd, an antimissile expert with more than a dozen patents and two major textbooks on warhead design to his credit. “But I’m not seeing the things I want to see” to prove that Iron Dome actually succeeded to the extent described by Israel.

Mr. Lloyd, who works for Tesla Laboratories Inc., a defense contractor in Arlington, Va., said he had studied dozens of publicly available photographs of spent rockets that landed on Israel. Few of them, he said, showed signs of damage from Iron Dome’s exploding warhead and the specific mechanism by which the interceptor is designed to make its kill — a dense spray of speeding metal fragments.

Bits Blog: In Israeli Attack on Hamas: Shock, Awe and Social Media

screenshot, via Twitter

2:01 p.m. | Updated Adding links to new Twitter message.

As Israel began an attack on Gaza on Wednesday, killing a top military commander of Hamas, the government also took to Twitter to live-tweet the strike as it unfolded.

@IDFSpokesperson, the official Twitter account for the Israel Defense Forces, sent more than 25 messages over five hours as the attack occurred. The account also shared videos taken from the helicopter that killed Ahmed al-Jabari, Hamas’s top military commander, and warned of other attacks should Gaza retaliate.

Israeli officials even started their own hashtag for the strike, #PillarOfDefense.

“The IDF has begun a widespread campaign on terror sites & operatives in the #Gaza Strip, chief among them #Hamas & Islamic Jihad targets,” the Israeli military said on Twitter as the strike began.

This was followed by updates of the attack, including a 10-second video that showed Ahmed al-Jabari’s car being blown up as it traveled down a Gaza street. Officials then shared a link to the official I.D.F. blog, which explained who Mr. Jabari was and why the attack was important to Israel.

A Twitter message from the I.D.F. that warned other Hamas members, “whether low level or senior leaders,” not to show their heads in the coming days, was retweeted more than 2,500 times.

Terrorist organizations have long used Twitter and other social media sites to share their own accounts of attacks or hostage-takings. During the Iraq war, insurgents shared videos on Live Leak, another social video site, of homemade bombs that were used against the American military and video of snipers who had shot and killed United States Marines. But this was most likely one of the first times that a government organization had taken to Twitter to announce a military attack as it unfolded.

An Arabic Twitter account believed to be run by the Alqassam Brigades, the well-armed organized military wing of Hamas, responded to the I.D.F. on Twitter saying, “Our blessed hands will reach your leaders and soldiers wherever they are (You Opened Hell Gates on Yourselves).” The Alqassam Brigades has also been updating its Twitter account to describe areas in Israel it is attacking with projectiles.

The Hamas information Twitter feed, also said to be a Twitter account for Hamas, did not respond to the I.D.F. Twitter account. It is also not verified as an authentic account.

“There are 2 main goals of this IDF operation: to protect Israeli civilians and to cripple the terrorist infrastructure in the #Gaza Strip,” the I.D.F. wrote.

After the attacks concluded, the I.D.F. sent a Twitter message that said: “Ahmed Jabari: Eliminated.”