Israel-Iran escalation: How strong are their militaries?

Despite tit-for-tat attacks by Israel and Iran over the past week — the most recent of which occurred on Friday as Israel reportedly launched a drone attack in Isfahan — both sides seem reluctant to engage in an all out war. 

But in case of an extended armed conflict between Israel and Iran, Israel would have to reckon with factors that are difficult to assess. 

The most pressing aspect is whether Iran's non-state allies would take part in such a conflict.

Iran's most important ally in the Middle East is Hezbollah in Lebanon.

Furthermore, the Houthi militia in Yemen and a number of Shiite militias in Iraq could also become involved or be recruited by Iran as military supporters.

"Israel has been long preparing for the risk of such a multi-front war," Arye Sharuz Shalicar, a spokesperson for the Israeli army, told DW.

The focus has been on three aspects in particular, he said.

Firstly, the expansion of defence systems, especially air defence systems such as the Iron Dome, Patriot, David's Sling (also known as Magic Wand) and the Arrow system.

"At the same time, offensive capabilities are being continuously developed," Shalicar said, adding that "defence alone might not be sufficient but according to the motto 'attack is the best defence', a counter-attack could be a necessary step," he added.

And as a third measure, Israel is working on a broad regional and international alliance, Shalicar said.

Comparable army strength

According to the Global Firepower Index 2024, the Israeli and Iranian militaries are not too far apart in terms of overall military power.

Iran is ranked 14th in the global ranking, followed by Israel in 17th place.

The index has also included a direct comparison of the two armed forces. According to this, Iran is superior to Israel in terms of manpower. The same also applies to the number of tanks and armoured vehicles.

However, given the geographical situation, these are not the most relevant factors in case of an armed conflict between Israel and Iran.

The states are separated by neighbouring countries such as Iraq and Jordan, and the distance between Jerusalem and Tehran is around 1,850 kilometres (1,149 miles).

"In fact, a conflict would not take the form of a classic war, but would rather be an exchange of blows over long distances," says Fabian Hinz, Middle East expert at the London-based International Institute for Strategic Studies, or IISS.

An armed conflict between Israel and Iran would primarily be conducted by air, he added.

Air forces play an important role

Israel is clearly superior to Iran in terms of air power, according to the Global Firepower Index. In total, the Israeli army is equipped with 612 fighter jets, while Iran has 551.

Beyond the figures, it is also the quality of the military aircraft that matters, Hinz told DW.

In case of a conflict, aviation will play a very important, perhaps even the decisive role for Israel, he said.

"On the Iranian side, however, aircraft do not have a noteworthy significance, as it has hardly been possible to renew the fleet due to sanctions," Hinz said.

Iran was able to buy some aircraft in the 1990s and would now like to acquire some Russian-made planes, he added.

"But basically they know that they can't keep up with the Israeli air force," Hinz said.

This is why Tehran has focused primarily on the development of missiles and drones. However, it is questionable how well these could fend off an Israeli air attack. "I assume that this would not be particularly successful," Hinz said, adding that "Iran does not have a serious defence shield."

Absolute protection impossible

Nevertheless, the recent Iranian drone and missile attacks have revealed where Israel needs to make improvements, Alexander Grinberg, an Iran expert at the Israeli think tank Jerusalem Institute for Strategy and Security, told DW.

"In principle, it's rather easy to shoot down such drones, because they're not very speedy," he said, adding that this could be even done with simple machine guns.

However, it is not only the type of drone but also the number that matters.

"On Sunday [April 14, when Iran attacked Israel] it became clear that you also have to be able to fend off an attack by a large number of drones and Israel must be prepared for this," Grinberg said.

Some of the missiles were brought down by Israel's allies.

The Iranian attack has also demonstrated that there is no such thing as a hermetically sealed system, army spokesman Shalicar said.

"Whether 300 or 3,000 missiles are fired, ultimately some will always penetrate the defence shield which is why the hit rate at the weekend was not 100%, but around 99%," he said, adding that "this makes it all the more important to have a functioning civil homeland defence system, in other words an early warning system and air raid shelters."

Potential game changer: Hezbollah

However, an armed conflict with the Lebanon-based Hezbollah would be a different kind of military challenge for Israel.

Hezbollah, often referred to as the "spearhead of Iran," is probably the most heavily armed non-state group in the world, according to a study by the Center for Strategic and International Studies in Washington.

The EU classifies the military wing of Hezbollah, which has repeatedly attacked Israel with rockets, as a terrorist organisation.

Estimates of Hezbollah's rocket stock vary between 120,000 and 200,000 and, according to the CSIS study, Iran would be able to quickly supply the Hezbollah militia in the event of war.

The majority of its arsenal consists of unguided short-range projectiles, though the militia has also greatly improved its access to long-range missiles, IISS's Hinz said.

In addition, the group could also attack from Syrian territory, he added.

"This means that a large part of Israel will be threatened by Hezbollah attacks in the event of an escalation of the conflict," he said.

Israel would be able to use the Iron Dome system against missile attacks from Lebanon, Hinz said, adding that "in general, these defence systems are always ready for use and they work extremely well, however, the number of rockets remains the main problem in my view."

Kersten Knipp is a political editor at Deutsche Welle with a focus on the Middle East.

Disclaimer: This article first appeared on DW, and is published by special syndication arrangement.