What is Israel's Iron Dome air defence system and why was Hamas still able to attack?

Israel’s Iron Dome was created in 2011

A salvo of rockets is fired by Palestinian militants from Gaza as an Israeli missile launched from the Iron Dome defence missile system attempts to intercept the rockets, fired from the Gaza Strip, over the city of Netivot in southern Israel .

Israel is known for its “Iron Dome” defence system, which was set up with financial support from the US twelve years ago.

Questions have been raised as to how Hamas attacks managed to get through air defence when it launched an unprecedented assault on Israel at the weekend.

What is the Iron Dome air defence system?

Israel created the system in 2011 to protect itself against attacks from militant groups such as Lebanese organisation Hezballah and Palestinian group Hamas.

Conflict in the region in the 1990s and early 2000s prompted the Israeli government to look at creating an air defence system.

The sophisticated system can intercept and destroy short-range rockets and artillery shells fired from distances of 2.5 miles to 43 miles into Israeli territory.

From 2011 to 2021, the United States contributed a total of $1.6 billion to the system, with another US$1 billion approved by the US Congress in 2022.

Did it work?

When Hamas attacked on Saturday, it is estimated 2,500 to 5,000 rockets (figures from both sides have differed) were fired from Gaza into Israeli territory.

While many were intercepted by air defence, it is understood that the sheer number meant some were able to get through.

It is also believed that small drones were used to drop munitions on military targets in Israel.

When detection radar from the Iron Dome detects a rocket in the air, a control system calculates the trajectory and potential target. It then launches missiles to counter it.

Some experts, however, have warned that the system was overwhelmed. The Iron Dome has a limited number of Tamir interceptors.

“The entire system failed. It’s not just one component. It’s the entire defence architecture that evidently failed to provide the necessary defence for Israeli civilians,” Jonathan Conricus, a former international spokesman for the Israel Defence Forces (IDF) told US news outlet CNN.

Where did Hamas’ weapons come from?

Tunnels which at one time allowed Hamas to smuggle in weapons across the Egyptian border have long been sealed, as far as possible.

However, it has been widely reported that Iran has backed Hamas, supplying the organisation with blueprints and information about building weapons within Gaza – as well as supplying components which are smuggled in across land borders. Iran has insisted it has not been involved in the latest attack, although Hamas has reported it had Iranian backing.

It is thought Hamas has tens of thousands of weapons stockpiled.

What is Israel’s smart border with Gaza?

While thousands of rockets were fired in Saturday's attack, perhaps more significant was the militants who were able to enter Israel to kill civilians and take hostages. Israeli authorities say dozens of people have been captured by Hamas, with many taken back to Gaza. The militants also stormed a music festival taking place near the Gaza border, killing 260 people. Others at the festival were kidnapped.

In total, more than 700 people have been killed in the assault, while a further 500 have been killed in Palestine.

Israel has spent hundreds of millions of dollars building a smart border system with sensors and subterranean walls that was believed to have been completed at the end of 2021.