How do the Israeli military and Hamas compare in size and strength?

On Saturday, Hamas attacked a music festival in southern Israel, killing at least 260 people. The surprise air and ground assault included the execution of civilians in the streets.

Israel has returned Hamas' rocket fire and blocked off the entry of food, fuel, water and medicine supplies to Gaza, as well as prompting the shut down of Gaza City's only power station as a huge humanitarian crisis unfolds.

As of Friday, the conflict has led to the deaths of over 2,800 people - more than 1,500 Palestinians and at least 1,300 Israelis have been killed.

Israeli leaders said they are preparing to "execute the mission" against Hamas, warning every member of the militant group is a "dead man".

The Israeli Defence Forces (IDF) mobilised hundreds of thousands of military reservists near the Gaza border ahead of a feared ground invasion.

Hamas and the IDF are two very different military powers in size and strength.

ITV News spoke to an expert about what the future looks like for Israel and Palestine.

How do the IDF and Hamas compare in size?

According to the International Institute for Strategic Studies' (IISS) Military Balance 2023, Israel has 169,500 active military personnel in the army, navy, and paramilitary.

Crucially, a further 465,000 constitutes its reserve forces.

"It's an army equipped to fight at a fairly high intensity," Dr Sidharth Kaushal, a military sciences expert with the Royal United Services Institute, told ITV News.

"Under wartime conditions, (its size) can go into the hundreds of thousands.

"In terms of strength and the sort of capabilities it fields, it fits effectively what one would expect from a western army."

How does Hamas compare? The official numbers are unclear.

In 2021, The Times of Israel quoted an unnamed senior Israeli commander as saying Hamas had an army of 30,000 men.

"Obviously, there's also a question of skill and training where there's a considerable difference between the IDF and Hamas' personnel serve," Dr Kaushal said.

What weapons do the armies have at their disposal?

Israel's defence budget, including US aid, is believed to be around $23.6 billion (£19 billion) in 2023.

Alongside its mammoth wartime size, the IDF has a "a very capable" modern air force, according to Dr Kaushal, as it is equipped with developed aircrafts like the F-15, F-16 and the F-35.

It also has its highly effective Iron Dome missile defence system, designed to shoot down incoming projectiles - the type that Hamas are currently firing.

Watch Israel's Iron Dome in action as it intercepts rockets fired by the Hamas militant group

To an extent, the Israeli military does depend on its partnership with the US. Joe Biden has already pledged to stand by Israel, seemingly giving the green light for a continued operation which may include a ground incursion, and replenished its Iron Dome munition.

"The US maintains forward-deployed war stocks in Israel which meet some of the ideas, contingencies, requirements, in a crisis," Dr Kaushal explains.

Hamas, in contrast, is a little more limited with a much lower budget to fight with.

"There's a qualitative discrepancy in pretty much every category of equipment," said Dr Kaushal.

"It's a relatively primitive force.

"Unlike, for example, Hezbollah to the north, which has adopted some of the trappings and capabilities of a conventional military, (Hamas) is still really more of an insurgent force that cannot very easily defend terrain against the IDF.

"It does not have as much of a credible anti-armour capability... And they still lack precision in terms of the rockets they use."

The militant group is known to have a long-running relationship with Iran, who has been a financial supporter of Hamas for a number of years.

They have also donated military hardware, including missiles, and Tehran is now facing claims they helped instigate Hamas' attack at the weekend.

What strengths do Hamas have?

Despite the technological pitfalls, there are elements Hamas have been able to leverage, Dr Kaushal explains.

"The first is asymmetry of cost, particularly when you think of a rocket attack," he said.

"Because interceptors are very expensive (for Israel)... costing around $80,000-$100,000, and the rockets they are intercepting are quite cheap.

"There has been a growing threat to Israel's air and missile defence systems over the years of just being saturated... so that that has posed a challenge."

The second crucial component working in Hamas' favour - an element they can exploit - is the human terrain of Gaza.

"The fact that Hamas can force the IDF into battling in an urban environment, in an area where it has significant underground infrastructure and it's quite well dug-in," said Dr Kaushal.

"Where even quite capable modern militaries can struggle to root out comparatively primitive opponents.

"So although it's obviously a massive asymmetry in terms of specific capabilities, there are certain advantages of both geography and cost which Hamas appears to be trying to leverage."

What happens next?

"Israel certainly has the strength to launch a ground invasion of Gaza, and they probably will," Dr Kaushal said.

"The question, I suppose, is whether as in previous instances, they launch a shallow incursion to destroy tunnels, or a more all-out assault to root Hamas out of Gaza and destroy its infrastructure.

"The latter is two fold, the question of how well prepared Hamas is to conduct an urban defence - as I said, militant groups can be quite difficult to root out of forbidden terrain. You think of ISIS in Mosul, for example.

"The second question is what Israel's war aims are - are they destroying the infrastructure? Is it regime change in Gaza? In which case, a military result can be easy to achieve, but sustaining a friendly regime after it is more tricky.

"A ground incursion of some kind in Gaza is very likely. In terms of what Israel's war aims are with that incursion, I'd say we have less clarity at this point."

Is this just the beginning?

Many Israeli politicians "look to be stealing themselves for a long war against Hamas," including Prime Minister Benjamin Netanyahu.

"It's hard to say for sure," Dr Kaushal adds.

"But certainly, it's difficult to envision this being over very quickly."

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