The American Wall Street Journal said that the Hamas movement has become more sophisticated and its fighters more powerful than the last time Israel invaded the Gaza Strip nearly a decade ago where “Israel crushed an unparalleled Hamas fighting force, destroyed tunnel systems and closed smuggling routes, costing the Islamist group Hamas two-thirds of its missiles by the time Israel withdrew.”

And now, according to the newspaper, “as Israel intensifies its new invasion, it faces a more powerful enemy that has rebuilt its arsenal with the help of Iran. Since the start of the operation on October 27, Hamas has attacked the Israeli army with drones loaded with explosives, anti-tank missiles and high-impact rockets, which are types of weapons that transformed the battlefield in Ukraine."

The newspaper notes that, “With 26 people killed in a week of the operation, Israelis are dying at a rate more than double the rate in 2014, when 67 people lost their lives during a seven-week campaign.”

The newspaper claims that at the heart of Hamas' ability to respond to the invasion lies the group's long-standing relationship with Iran, which has continued to support Palestinian resistance fighters with money and technical expertise, "as in the months preceding the October 7 attack, hundreds of Hamas members went to Iran for military training."

The newspaper attributed to Avi Melamed, a former Israeli intelligence official, that while he expects Israel to eventually win, the advanced arsenal means that Israel will have to prepare for a long-term conflict. Melamed said: “Hamas is a major military force thanks to Iran. They are well armed.”

Hamas used the experience to develop local skills in weapons manufacturing and collect weapons from materials available in the Gaza Strip, despite the Israeli and Egyptian siege of the Strip, which are the weapons it now uses to fight the Israeli army.

Some analysts say that even if Israel manages to deplete Hamas's military capabilities, the destruction wrought to achieve that goal could lead to a long-term insurgency once the campaign ends.

The United States has fought several wars against armed groups, including Al-Qaeda and the Taliban, but has faced long and stubborn insurgencies. Analysts say that eliminating Hamas may be more difficult.

The Wall Street Journal attributed Dan Byman, a senior fellow and expert on counterterrorism at the Center for Strategic and International Studies, to say: “Hamas has very deep roots, and this is different from Al-Qaeda, which was smaller.”

“Even if the defeat of Hamas deters Palestinians from joining the group, the Israeli attack will fuel anger among Palestinians, who may join other armed groups. Israel has given no indication of what comes after the military operation. It is likely that it will not maintain a presence of ground forces permanently stationed in the Strip, and no settler communities seemed willing to live there,” Byman said. “The most important thing is that even the United States had tangible support from the population who were willing to work with the United States; “A lot of Iraqis and Afghans work with them, but there are no Palestinians eager to work with the Israelis in Gaza.”

The newspaper quotes Marwan Abdel-Al, a senior official in the Popular Front for the Liberation of Palestine, a secular armed group based in Syria with operations in Lebanon, Gaza and the West Bank, as saying in an interview in Lebanon, “Hamas and its allies are better equipped to respond to an Israeli ground invasion than any other time before".

“Today, it's very different from 2014,” he said, pointing to drones, as well as the type of advanced guerrilla tactics developed by Iran's Islamic Revolutionary Guard Corps and Russia's Wagner Group.

The Front said it participated in the October 7 attacks, and that it continues to fire rockets at Israel from Gaza.

Abdel-Al warned that Israel would get trapped in quagmire, as Germany did in Russia during World War II or the United States in Vietnam. “The guys are there, on the ground, ready,” he said.

Hamas has been manufacturing rockets for more than two decades. The first generation of Qassam rockets, cheap sugar-powered rockets that Hamas began producing during the Palestinian uprising known as the Second Intifada, around 2001, had a range of 2 to 3 miles. The third generation, the Qassam 3 missiles, has a range of about 10 miles. Now, Hamas has offered missiles with a range of up to 150 miles, covering essentially all of Israel.

The newspaper claims, “In the past, Iran produced missiles in Sudan and smuggled them into Gaza through tunnels from Sinai with the help of Egyptian Bedouins. This has largely stopped now, since Egypt flooded the tunnels and Sudan began rapprochement with Israel and distance itself from Iran. Instead, Hamas and Islamic Jihad have moved to local production and are manufacturing explosives and weapons from raw materials, according to analysts.

Back in 2014, Hamas relied mostly on Soviet-era projectiles without a guidance system, most dating back to 1969.

Drones were rare in Hamas' hands about a decade ago, and those they did have were rudimentary models with limited offensive capabilities.

But in the new war, Hamas published videos targeting Israeli forces with munitions dropped by drones, damaging tanks and military vehicles.

Israeli forces also faced attackers equipped with North Korean-made F-7 high-explosive missiles. the Kornet mobile anti-tank guided missile, a model developed in Russia but often copied by Iran; and locally made "Al-Yassin" anti-tank missiles.

Hamas has developed a strong domestic weapons manufacturing capacity that relies in part on the transfer of Iranian technology.

It manufactured a drone called Ababil, which was developed based on an Iranian design.

Hamas also has a locally produced drone called “Al-Zouari,” named after Tunisian engineer Mohammed Al-Zouari, who helped develop the weapons and was assassinated in Tunisia in 2016, a killing that Hamas blamed on Israeli intelligence.

Perhaps Hamas's strongest defense is a vast network of tunnels extending like an underground city, where fighters, fuel and weapons are located, and "where Hamas has been holding hostages since October 7," according to the newspaper.