Are Israeli Operations Against Gaza Rockets Productive?

Since 2005, Hamas and other Gaza militants have fired over 12,000 rockets at Israel. They caused at least ten deaths, over 1,100 injuries, and over $50 million in property damage. The Israeli Defense Forces (IDF) responded with three military operations against Gaza. Their stated goal was to protect Israeli civilians from the rockets.

HOW PRODUCTIVE WERE ISRAELI OPERATIONS RELATIVE TO THEIR GOALS? WERE THEY EFFECTIVE AND EFFICIENT AT PROTECTING ISRAELIS FROM ROCKETS?

All those issues are important, but they overlook a key underlying question. How productive were the operations relative to their goals? Leaving aside their many secondary effects, were they effective and efficient at protecting Israelis from rockets?

Rocket data summary from "The Effectiveness of Rocket Attacks and Defenses in Israel" (via the author)

I have explored this issue in a study of Israeli rocket countermeasures covering Operations Cast Lead in 2008-2009, Pillar of Defense in 2012, and Protective Edge in 2014. The research estimated the operations’ effects, benefits, and costs. With limited data available, the estimates are rough but nonetheless informative.

The daily fire rates during airstrike periods were also twice as consistent during Protective Edge relative to the earlier operations. The militants apparently had improved their ability to sustain operations under fire, perhaps thanks to their tunnel network.

ROCKET FIRE RATES DID DECREASE SIGNIFICANTLY AFTER GROUND FORCES ADVANCED DURING CAST LEAD AND PROTECTIVE EDGE. BUT THESE OPERATIONS WITH GROUND ASSAULTS INCURRED MUCH GREATER EXPENSES PLUS MILITARY CASUALTIES.

Rocket fire rates did decrease significantly after ground forces advanced during Cast Lead and Protective Edge. Controlling the ground in Gaza helped the IDF control the air over Israel.

By destroying rockets preemptively, the IDF prevented them from harming Israeli civilians. For example, Cast Lead’s twenty-three-day air-land offensive claimed 1,200 destroyed rockets. If those had launched, they could have potentially increased civilian casualties by some 194 percent. That implies the rocket destructions prevented roughly six deaths and 274 injuries, or 280 casualties in total.

Pillar of Defense destroyed 980 rockets but only kept civilian losses from being 72 percent higher, avoiding four deaths and 173 injuries. The smaller impact follows from the operation lasting just eight days and lacking ground assaults. Israel’s civil defense expansions and Iron Dome interceptor deployments also contributed to the reduced casualty prevention.

Protective Edge’s impact was surprisingly modest, given its forty-two days of fighting and its intensive ground assaults. It prevented rocket casualties from being 101 percent higher, thereby avoiding just two deaths and eighty-four injuries. The number of rocket destructions exceeded 3,000, more than the previous two operations combined. However, the value of those destructions dropped due to Israel’s other countermeasures. Increasingly influential Iron Dome interceptors meant that just eight percent of rockets evaded interception and hit valuable targets. Improving civil defenses meant fewer such hits caught victims unsheltered.

Pillar of Defense was the least expensive operation, thanks to its brief duration and air-only nature. Dividing the IDF’s marginal cost by the number of rockets destroyed indicates an average cost of $290K per rocket eliminated. Alternatively, dividing by the total number of avoided dead and wounded implies a price of $1.6 million per civilian casualty prevented.

Operations with ground assaults incurred greater expenses plus military casualties. Cast Lead averaged $870K per destroyed rocket. Its price per civilian casualty prevented was $3 million plus 0.2 IDF casualties.

Protective Edge’s cost per destroyed rocket was $560K, midway between the other two. Unfortunately, the operation incurred far more military casualties than the civilian ones it prevented. Its price per civilian casualty avoided soared to $19 million plus 4.7 military casualties.

The rough pricing above simplistically assumes rocket loss prevention was the operations’ only goal. Factoring other missions into this analysis would reduce the expense attributable to anti-rocket efforts. For example, if tunnel destruction unrelated to rockets generated at least eighty percent of the IDF casualties during Protective Edge, then the civilian casualties prevented begin outnumbering the military ones suffered. However, the price estimates also ignore the IDF’s capital and fixed expenses. Including those would increase the prorated estimates.

The calculations similarly ignore any deterrence benefits because they seemed minimal during the 2005-2014 period. In what the IDF informally called “mowing the grass,” one operation followed another every few years, with hundreds of rockets fired in between. Since 2014, Hamas has seemed deterred from firing rockets, though not from building them. The potential benefits of any limited deterrence would need to be set against the ongoing costs of the IDF deterrent force.

This discussion also ignores Israel’s indirect economic losses because of rocket fire. For example, during Protective Edge the country’s economy lost about $1 billion, or $24 million per combat day.

These results suggest that the military operations have become less effective and less efficient at preventing civilian casualties. The IDF seems good at destroying rockets; however, such preemptive strikes matter less because Israel’s civil defenses and interceptors have gotten better. Airstrikes by themselves reduce the rocket stockpiles but not the fire rates. Ground assaults do suppress rocket fire but also boost costs.

 How Israel’s Iron Dome Actually Works (via Bloomberg)

Another part of my research showed that Israel suffered relatively few rocket casualties only because of its combined countermeasures: military offensives, rocket interceptors, and civil defenses. For example, rocket fire during Protective Edge directly hurt only about 85 people. Without the country’s countermeasures, that count could have been over 50 times higher, around 4,500.

Taken together, these results imply that criticism about the operations is partly misplaced. On the one hand, Israel’s rationale for military operations may be better than critics admit. Although the rockets inflict “low” actual losses, they pose a high potential threat. Perhaps its critics should consider not only the hundreds of casualties the country experienced but also the thousands more it could have suffered absent its preparations?

On the other hand, the operations’ benefits seem increasingly not worth their costs. Perhaps there should be less debate about the operations’ proportionality and more about their productivity?

These implications should be considered before leaders contemplate future anti-rocket operations. Hamas has over 10,000 rockets in Gaza, where tensions have recently spilled over the Israeli border. Hezbollah has 120,000 it could employ if the increasingly-discussed “Northern War” erupted with Israel. My analysis is too narrow to say whether such operations should or should not be launched, but it suggests their net benefits may be less than expected.

Finally, one might try extrapolating these results to other contexts, like potential U.S. strikes against North Korea. ICBMs with 20 kiloton nuclear warheads are worlds apart from rockets carrying 20kg explosive charges, but some issues are qualitatively similar. For example, even if the U.S. preemptively destroys many North Korean missiles, how effective would that be at preventing South Korean, Japanese, and American casualties? Are those countries’ missile interceptors and civil defenses good enough to prevent most civilian losses? If so, successful preemptive strikes against North Korea might offer little net benefit; if not, unsuccessful strikes could allow horrendous casualties. Would air and cruise missile attacks suffice, or would more costly ground assaults also be needed? Hopefully, these questions will remain strictly theoretical.

Michael J. Armstrong is an associate professor of operations research at Brock University. He studies navaland land-based missile combat. His research on “The effectiveness of rocket attacks and defenses in Israel” appears in the Journal of Global Security Studies.

This article appeared originally at Strategy Bridge.