Israel's Iron Dome aerial defense system is launched to intercept a rocket launched from the Gaza Strip, above the southern Israeli city of Ashdod, on May 17, 2021.

Israel's Iron Dome aerial defense system is launched to intercept a rocket launched from the Gaza Strip, above the southern Israeli city of Ashdod, on May 17, 2021. AFP via Getty Images / Ahmad Gharabli

US Must Strengthen Israel’s Deterrence

As Israel’s adversaries look to rearm and improve their own capabilities, Washington must act to help Israel deter another fight.

President Biden's public pledge to replenish Israel’s Iron Dome would boost Israeli defenses, but is insufficient to deter another war. To minimize the potential for another conflict, Israel needs further upgrades to its air defenses and access to advanced U.S. precision weapons.

Since the last major war between Israel and Gaza in 2014, Iron Dome has been upgraded to better intercept drones and large barrages of mortar fire. In March, the air defense system intercepted about 1,600 of the 4,360 Palestinian rockets and mortars that would have struck populated areas. With the Iron Dome’s protection in place, the IDF has greater freedom to choose how and when to respond to aggression.

Yet Palestinian militants significantly increased their rate of fire in this latest conflict to try and overpower Israel’s defenses and bolster their image. Palestinians launched 3,600 rockets in 11 days last month, compared to 3,700 over the fifty-day war in 2014. Hamas and Palestinian Islamic Jihad demonstrated that they can occasionally penetrate the Israeli system’s protection by simultaneously launching large barrages of projectiles at a single target.

Deterring these kinds of attacks requires improving Israel’s ability to precisely target their launch sites and intercept synchronized bombardments of missiles, rockets, mortars, and drones.

Israel’s limited supply of Iron Dome batteries is another problem, especially when facing the increasing precision and range of Palestinian rockets. Each of Israel’s reported 10 Iron Dome batteries can cover a medium-sized city, but that still leaves other cities or infrastructure vulnerable to attack. Increasing the number of Iron Dome batteries that Israel has and therefore the amount of territory it can defend would deter its adversaries by denying them the ability to circumvent the system.

Additional Iron Dome batteries would allow Israel to better cover its territory while also reserving batteries in case Iran or Hezbollah decide to launch a much larger war along its northern border. Iran, the main backer of Hamas, PIJ, and Lebanese Hezbollah, seeks to proliferate advanced precision weaponry throughout the region that could encircle Israel and overwhelm its air defenses. Hezbollah’s arsenal of roughly 130,000 rockets and missiles vastly surpasses what Israel faces in Gaza. Therefore, the United States should consider what Israel needs to deter and defend not only against Hamas but also a multifront war with Iran and Hezbollah.

Israel’s proven ability to destroy weaponry, tunnels, and command-and-control systems likely provides it with a level of short-term calm. The IDF claims to have degraded the capabilities of armed Palestinian groups, yet militants in Gaza have sizable arsenals that they can readily resupply by turning everyday items, such as metal pipes, into projectiles.

In preparation for a much larger war, Congress should quickly pass legislation funding President Biden’s pledge to replenish the IDF’s depleted stores of Iron Dome batteries, as it did when Israel faced a similar strain on its missile defenses in 2014. However, legislators should help Israel deter its adversaries by pushing America’s support beyond replacing these defensive weapons. Since Hamas proved it can put much of Israel under fire, Congress should also provide funding for Israel to purchase three to five additional Iron Dome batteries so that it can shield more Israeli population centers.

With Israel rapidly using its precision weaponry and needing to hold reserves in case of war with Iran or Hezbollah, Biden should also update America’s stockpile of prepositioned weaponry in Israel, named WRSA-I. This weapons cache has become obsolete and lacking in precision-guided munitions, Joint Direct Attack Munitions, and GBU-39 and GBU-53/B small diameter bombs that are necessary for waging war against the large arsenals of advanced weaponry that Iran or Hezbollah can field. In the short term, the Special Defense Acquisition Fund would enable the Pentagon to speed up the delivery of precision munitions, or the United States could lend Israel the weapons.

In the long term, the United States should cooperate with Israel on mutually beneficial research and development programs for improving the Iron Dome and other potential air defense technologies, such as directed energy. The U.S. Army has acquired two Iron Dome batteries, so any upgrades could improve U.S. deterrence as well.

As Israel's adversaries look to rearm and improve their own capabilities, Washington must act quickly to help Israel deter them from starting another fight. 

H Steven Blum, a retired U.S. Army lieutenant general, served as Deputy Commander of U.S. Northern Command. In 2015, he was a participant in The Jewish Institute for National Security of America’s (JINSA) Generals & Admirals Program.

Ari Cicurel is a Senior Policy Analyst at JINSA’s Gemunder Center for Defense and Strategy.