How Did Israel's Missile Defense Perform in the “12-Day War”?

Israeli missile defense intercept rates: expectations versus reality

Picture: Israeli Ministry of Defense

On the night of June 12, Israel launched a major air campaign — Operation Rising Lion — targeting Iranian nuclear facilities, ballistic missile sites, IRGC command centers, and assassinating high-ranking military and nuclear science personnel.

Iran responded with large-scale ballistic missile and drone strikes against Israeli military and countervalue targets, killing 28 Israelis and injuring around 1,400. On June 22, the United States joined with strikes on Iranian nuclear sites. A fragile U.S.-brokered ceasefire took effect on June 24, effectively ending what is now referred to as the “12-Day War”.

This post offers an initial assessment of the performance of Israeli missile defenses against the medium-range ballistic missile threat Iran mounted during the war and outlines some implications for NATO.

Expected intercept rates

Israel relies on a layered air and missile defence system to protect its territory.

The lowest tier is the well-known Iron Dome system, designed to intercept short-range threats such as mortar rounds and rocket artillery. At the middle tier, Israel employs the David’s Sling system, optimized for intercepting low-flying long-range drones, cruise missiles, and ballistic missiles with ranges up to 300 kilometres. The top layer consists of the Arrow missile defence system, which engages incoming ballistic missiles — including those launched from Iran with ranges exceeding 1,000 kilometres — outside the atmosphere.

From previous missile defence engagements in 2024, we know that the intercept probability of individual upper tier (i.e., Arrow 2 and Arrow 3) Israeli ballistic missile interceptors is likely around 80 to 90 percent. In other words, if ten interceptors are launched against ten incoming ballistic missiles, roughly eight to nine are expected to be intercepted, while one to two are likely to get through.

Of course, the intercept probability can be dramatically increased by launching multiple interceptors per target. With two interceptors, the success rate exceeds 96 percent. With three, interception is virtually guaranteed.

However, missile defense interceptors are costly and difficult to produce, with long lead times between order and delivery. Given that Israel’s stockpile had already been depleted by the Iranian missile salvos in 2024, it was expected that Israel would no longer have the arsenal depth to launch multiple interceptors at incoming targets.

Actual intercept rate

Following the conclusion of the ceasefire and initial reports, the actual intercept rate appears to have been higher.

Initial battle damage assassments suggest that Iran launched around 550 medium-range ballistic missiles. Of these, at least 31 are reported to have struck locations of strategic or civilian importance or near them (e.g., population centers, critical infrastructure, military headquarters). Dozens of others, likely an additional 25-40, are reported to have landed in open fields without causing damage.

Importantly, I should note that I have not attempted to independently verify these figures in detail. However, having followed the conflict closely on a day-by-day basis, including reports of individual salvos and the damage they caused, the numbers appear broadly plausible. Strikes in major population centers are extremely difficult to conceal, and I don’t see credible evidence that Israeli leadership has attempted to do so.

The larger unknown is likely how many of the warheads that landed in open fields were known to be heading there and were therefore not engaged — in line with Israeli missile defense doctrine — and how many did so by chance. Israeli missile defense radars are known to track the expected impact points of incoming ballistic missiles with relatively high accuracy. It is therefore likely that most, if not all, warheads landing in unpopulated areas were identified as such in advance.

In addition, not all ballistic missiles launched toward Israel are likely to have reached their targets. Some will have failed midair due to systemic error. I have not seen any Israeli or other official estimates for these failures. High-end Western conventional long-range strike weapons such as the JASSM-ER exhibit systemic error rates below ten percent. Given Iran’s decades of experience in developing medium-range ballistic missiles, I would estimate its systemic error rate at around ten to 15 percent, though some uncertainty remains.

Assuming a ten to 15 percent systemic error rate, roughly 480 to 500 medium-range ballistic missiles approached Israeli airspace as potential threats. Of these, 25 to 40 were assessed as non-threatening once their trajectory and expected impact point were identified. This suggests that Israeli missile defenses likely attempted to intercept between 420 and 475 missiles. Of those, 31 penetrated the defense shield, resulting in a failure rate of approximately 6.5 to 7.4 percent, or a success rate of 92.6 to 93.5 percent.

Again, these numbers are preliminary and require further confirmation. They also represent an average. In some instances, penetration rates appeared to have reached 10 to 20 percent, while in other Iranian salvos, zero or near-zero percent of incoming missiles hit any relevant targets.

Notably, Israeli estimates place the interception rate at around 90 percent, suggesting my estimate may slightly overstate actual performance. One possible reason is that I may be undercounting missiles that were assessed as a threat but ultimately missed any relevant target, or that I may underestimate the systemic error rate of Iranian medium-range ballistic missiles.

Why did Israeli missile defense again perform so well?

Given the expected intercept rate of 80 to 90 percent, Israel may have slightly outperformed missile defense expectations. Why was this the case?

First, and as confirmed by Israel’s defense industry, IAI — the developer of the Arrow missile defense system — used previous missile defense engagements in April and October 2024, as well as smaller launches prior to this episode, to improve Arrow’s performance at the software level. The more data gathered on successful and failed intercepts, the more refinements can be made to target tracking and interceptor cueing algorithms.

Second, Israel likely never reached the point of full arsenal depletion, though it may have come close. Its air interdiction campaign likely played a significant role in reducing the number of Iranian ballistic missile threats by intercepting them before launch.

U.S. support with regional missile defense assets, particularly two ground-based THAAD batteries and ship-based interceptors launched from the sea, also likely played an important role. This support allowed Israel to conserve its own interceptor arsenal. According to open-source estimates, the United States launched at least 36 THAAD interceptors during the war.

Third, the layered structure of Israel’s missile defense network enabled a “shoot-look-shoot” approach: an initial intercept is attempted in the upper tier using the Arrow system, and if that fails and the failure is confirmed, a second attempt can be made in the medium tier using David’s Sling.

Imagery from the war confirms that Stunner interceptors, used in David’s Sling, successfully engaged incoming medium-range ballistic missile warheads. This is notable, as Stunner is optimized — and nominally rated — for intercepts against threats with ranges up to 300 kilometers. In this sense, the system outperformed its known specifications.

Even more surprising, video footage has emerged showing Tamir interceptors — used in the Iron Dome system at the lowest tier — intercepting what appears to be a medium-range ballistic missile warhead at an estimated altitude of five to seven kilometers.

Nominally, Tamir interceptors are not designed to engage such threats, let alone succeed in doing so. That they did speaks to the strength of Israel’s defense industry and Iron Dome operators. It also suggests that some intercept attempts were made under conditions of considerable urgency.

Overall, the shoot-look-shoot approach likely increased the total number of successful intercepts while minimizing the number of high-tier interceptors that had to be expended.

Concluding thoughts

Much remains to be examined about the 12-Day War, both in terms of Israeli missile defense and Iran’s ballistic missile capabilities. Regarding the latter, a key takeaway is that unless Iran significantly improves the accuracy of its medium-range ballistic missiles, the credibility of its conventional missile deterrent will remain limited.

Another important point is that missile defense is not “hermetic”, a message repeatedly emphasized by the Israeli Defense Forces, which urged the population to take shelter during air raid alarms. This was true even for Israel, which fields the world’s densest and one of the most capable missile defense networks, backed by an extensive air interdiction campaign, together with regional missile defense assets provided by allies.

If the result in this close to best-case scenario was an intercept rate of 90 to 93 percent, it is doubtful that European NATO states would be able to match that performance in a war with Russia.