Stopping the Iranian attack would have forced Israel to deploy sophisticated – and expensive – defenses | Israel

Iran's decision to fire about 180 high-velocity ballistic missiles at Israel suggests that, in contrast to the high-profile drone and missile attack in April, Tehran sought to cause serious damage with Tuesday's night attack.

Their sheer speed makes ballistic weapons difficult to intercept, but initial reports of no fatalities in Israel and one in the West Bank suggest it was a military failure, despite the number of rockets fired, although some of the weapons or fragments appeared to be have hit the ground.

Tehran's Emad and Ghadr missiles, deployed earlier this year, are estimated to travel at least six times the speed of sound on impact and travel from Iran in 12 minutes. That would be more than 4,600 miles per hour. But Iran said it had deployed the even faster hypersonic Fatteh-2, whose top speed is estimated at 10,000 miles per hour.

Iran is estimated to have an arsenal of around 3,000 ballistic missiles, although the original calculation was made by the US two and a half years ago, so the number could well be higher. In the event that the conflict with Israel escalates further into a full-scale war, Tehran will want to retain most of its holdings.

Firing so many ballistic missiles in a few minutes also represents a serious attempt to overwhelm or exhaust Israel's air defenses. Because they are highly sophisticated, the interceptor missiles are expensive – and their stocks are uncertain.

Stopping ballistics in flight is primarily the task of the American-Israeli long-range Arrow 3 and Arrow 2 systems, first used during the Israel-Hamas war and supported by the medium-range David's Sling system. The more famous Iron Dome is used to intercept short-range rockets, often rockets fired by Hamas from Gaza.

In April, a former financial adviser to the IDF chief of staff said that an Arrow missile typically costs $3.5 million (£2.8 million) each and David's Sling interceptor costs $1 million (£800,000). Eliminating 100 or more missiles would easily cost hundreds of millions of dollars – although the missiles themselves would have cost Iran £80,000 or more each.

At the time, Tehran's Foreign Minister Hossein Amir-Abdollahian said it had informed neighboring countries 72 hours in advance of a planned attack – which came two weeks after the Israeli bombing of the Iranian embassy in Damascus. This time, Iran acted just days after Israel killed Hezbollah leader Hassan Nasrallah on Friday.

However, about a few hours before the missiles were fired, warnings began circulating from US sources that an attack would take place on Tuesday. It is unclear how the information would have been obtained, but it could have come from satellite images, intercepted communications messages or a diplomatic message. There were unconfirmed reports that Iran notified Russia before the attack.

It is not immediately clear how many Iranian missiles hit the ground; In the April attack, of the 120 ballistic missiles fired by Iran, only nine got through and caused minor damage to two air bases, meaning in a strict military sense that this attack was also a failure.

Iran deployed more than 300 drones, cruise missiles and ballistics in April, but stopped using slower-flying drones on Tuesday – an indication that they are considered ineffective against an adversary with a sophisticated air defense system. Cruise missiles may not have been used either.

Shahed drones, which are also heavily used by Russia in Ukraine, are relatively slow and can be easily shot down by fighter jets. Cruise missiles rely on maneuverability to evade air defenses, but are also slow compared to ballistic weapons – Iran's Paveh cruise missile travels at about 800 km/h.

Ukraine, which has been under constant attack by Russian missiles and drones since the full-scale invasion began, released its own interception rates in August. Its success rate would be lower than Israel's, partly because the country has had some types of short-range interceptor missiles due to the length of the war.

Ukraine's Commander-in-Chief Oleksandr Syrskyi said that while 63% of drones were intercepted and 67% of cruise missiles were stopped, this proportion fell to 4.5% for Russian ballistic missiles.