Iran on Saturday night launched dozens of drones, as well as missiles, towards Israel in an unprecedented direct attack on the state.

The attack will once again put Israel's Iron Dome, its short-range intelligent missile defense system, to the test.

What is Iron Dome and how does it work?

Iron Dome is actually the inter-operation of a system of radars, a control center and interceptor missile launchers that fire guided rockets to stop attacks in mid-air.

If a system of radars detects an incoming attack, it forwards the data to a command center that assesses whether the attack poses an actual danger. If it does, then guided interceptor missiles are deployed to detonate the attacking missile before it lands.

While the system is highly effective, the Washington-based Center for Strategic and International Studies (CSIS) estimates that the cost of producing a complete battery — consisting of the radars, command and control center and missile launchers — is as much as $100 million, while each of its guided missiles costs up to $50,000.

The Iron Dome also has a saturation point, after which it can’t stop more attacks coming in simultaneously.

The system was designed to protect against unpredictable, indiscriminate attacks fired from up to 70 kilometers away, though its critics claim it is susceptible to mortar attacks and projectiles fired from closer than four kilometers.

According to the Center for Strategic and International Studies, a US-based think tank, there are 10 mobile Iron Dome batteries operational in Israel. The anti-ballistic missiles they fire, known as Tamirs, rely on an autonomous guiding system. This allows them to reroute mid-flight based on data from the radars to stop attacks in mid-air, which are usually ballistic rockets that follow a human-guided course that can't be altered after launch. The interception reportedly only takes place if the command and control center determines it poses a real threat (e.g. headed toward a populated area).

How did Iron Dome come to be?

Political geographer Ian Slesinger traces the Israeli Defense Ministry’s interest in developing a missile interception system to an uptick in rocket attacks targeting southern Israel in 2005 after its withdrawal from Gaza.

Development began amid an "intensification of rocket fire from Gaza" in 2007, according to Slesinger, after the 2006 Hezbollah-Israeli war, during which Israel faced an onslaught of rocket fire from southern Lebanon.

Before becoming operational in 2011, controversy riddled Iron Dome’s development over its steep cost and whether Hamas and others’ tactics to overcome it would incur a higher civilian and military cost.

According to work published on the Institute for National Security Studies’s website by Israeli researcher Yiftah Shapir, the system was deployed to protect civilian areas, rather than military targets, after a popular outcry to prioritize safeguarding civilians.

What are the effects of the Iron Dome’s presence?

New York University researcher Shelly Yeini noted in a 2022 article that after the Iron Dome was deployed in 2011, the volume of rockets fired at Israel rose to multiples of its previous levels, demonstrating a conscious strategy of launching mass barrages to overwhelm the new defense system.

And yet, Yeini and Harvard Law School professors Oren Bar-Gill & Gabriella Blum, have argued in separate publications that the Iron Dome perpetuates military asymmetry, through which Israel incurs hundreds of Palestinian casualties with sometimes none on the Israeli side.

The researchers further question whether Israel's military responses, which include barrages that routinely kill hundreds, are proportional or justified, considering the relative protection afforded to Israeli citizens by Iron Dome.