Following October 7 terror attacks on Israel by Islamist militant group Hamas from the Gaza Strip, several Israeli officials have said they suspect the involvement of Iran, which is a known supporter of Israel-opposed militant groups in the Middle East.

In an interview with CBS News in the United States , Israel's ambassador to the US, Michael Herzog, said Israel's leadership suspected "Iranian hands behind the scenes."

"Hamas and Iran are closely tied. Iran provides material support, funding [and] weapons to Hamas," he said.

Israel's ambassador to the United Nations, Gilad Erdan, said that Iranian President Ebrahim Raisi met with Hamas leaders several weeks ago. "We know that there were meetings in Syria, in Lebanon," Erdan said.

"It's easy to understand that they tried to coordinate the military, the terror armies, the terrorists, the proxies of Iran in our region. They try to be coordinated as much as possible with Iran because, for the long term, the goal is to try and destroy Israel with the nuclear umbrella that Iran will provide them with."

On October 12, German Chancellor Olaf Scholz echoed this suspicion, telling legislators Iran had allowed Hamas to grow strong enough to the launch the latest attacks. While Scholz said there was "no firm proof that Iran operationally supported this cowardly attack, it is clear to us all that without Iranian support, Hamas would never have been able to launch this unprecedented attack."

Scholz also warned Lebanon's Iran-backed militant group Hezbollah against attacking Israel, saying this would further escalate the conflict.

What did Iran say?

Tehran has denied being involved in last weekend's attacks, which it has referred to as an act of "self-defense" by Palestinians. The Israeli government on Sunday declared it was at war with Hamas. Israel's death toll rose to an estimated 1,300 as of October 12 morning and dozens of hostages have been abducted. The death toll in Gaza has risen to 1,200, according to the Palestinian Health Ministry.

"Iran supports the legitimate defense of the Palestinian nation," Raisi said in a statement broadcast on Iranian state television while praising "resistance" efforts by Hamas.

Iran backs a broad network of militias and armed groups in the Middle East, including Palestinian groups, as Tehran continually seeks to consolidate its influence in Lebanon, Syria, Iraq and Yemen, as well as Gaza.

Iranian authorities consistently emphasize the term "axis of resistance" in their speeches and stances on Israel. This phrase denotes explicitly militant groups that have dedicated themselves to opposing Israel's right to exist and primarily includes Hamas and Lebanon-based Hezbollah. Both Hamas and Hezbollah's military wing are considered terrorist groups by several countries, including the US and the European Union.

Iranian officials hold regular meetings with these groups. In August, Iranian Foreign Minister Hossein Amir-Abdollahian met in Beirut with the heads of Hamas, the Palestinian Islamic Jihad, and other anti-Israel groups active in Lebanon. During this meeting, the foreign minister reaffirmed Iran's unwavering support for the "axis of resistance."

Israeli forces gather on a road near the border with Lebanon

Both Hamas and Hezbollah officials have consistently acknowledged the substantial support they receive from Iran. For instance, Mahmoud al-Zahar, a senior member of the Hamas leadership, said in December 2020 that he had received approximately $22 million (€21.6 million) in cash during a meeting with Qassem Soleimani, the former commander of the Revolutionary Guards' Quds Force, in 2006.

Hassan Nasrallah, the leader of Hezbollah, has repeatedly affirmed that the group receives financial support, weaponry, and missiles from Iran. For instance, during the summer of 2016, he said, "As long as Iran has money, we have money. No law can prevent receiving this aid."

A 2021 report from the Wilson Center, a US-based think tank, says that since at least 2006, Iran has been "focused on supplying its regional allies and proxies, including Palestinian factions, with the knowhow and equipment to produce rockets locally."

The report cites an interview with the commander of Iran's Revolutionary Guards' Aerospace Force, Amir Ali Hajizadeh, as saying, "Instead of giving them a fish or teaching them to catch a fish, we taught our allies and friends how to make a hook, and they are now in possession of missile capabilities and technologies."

Iran opposes Israel's budding ties with Arab countries

The Hamas attack also comes amid negotiations over diplomatic normalization between Saudi Arabia and Israel, which Iran opposes.

In a recent interview, Mohammed bin Salman, the Crown Prince of Saudi Arabia, mentioned that his country is "gradually progressing towards normalizing relations with Israel."

The Abraham Accords, signed in August 2020 by Israel, the United Arab Emirates and the United States, led to the normalization of relations between some Arab countries and Israel. However, Iran strongly opposes this approach taken by Arab nations.

On October 3, just four days before Hamas launched its attack on Israel, Ali Khamenei, the supreme leader of the Islamic Republic, characterized the establishment of relations with Israel as a "completely futile endeavor."

On Wednesday, Iranian President Raisi and Saudi Arabia's de facto ruler Saudi Crown Prince Mohammed bin Salman discussed the ongoing situation, with the Saudi leader affirming "the kingdom's firm position towards supporting the Palestinian cause."

And more recently, Raisi and his Syrian counterpart Bashar Assad urged Islamic countries to unite over the Palestinian cause. Raisi reportedly told an Iranian news agency, "Islamic and Arab countries as well all free people of the world" must together side against Israel and back the "oppressed Palestinian people."

Iran avoids direct involvement

A report published Sunday by The Wall Street Journal quoted unnamed officials from Hamas as saying Iran's Islamic Revolutionary Guard Corps helped plan Saturday's multi-pronged surprise attack on Israel.

However, on Monday, Israel Defense Forces spokesperson Daniel Hagari said, "Iran is a major player, but we can't yet say if it was involved in the planning or training."

Iran has denied it played a role in the attacks.

On Wednesday, The New York Times reported that US intelligence indicates key Iranian leaders were in fact surprised by the recent Hamas assault.

Raz Zimmt, an expert on Iran at the Institute for National Security Studies (INSS) at Tel Aviv University, responded to the claims made in the The Wall Street Journal article on X, formerly Twitter.

"While there is no doubt about the military cooperation between Iran and Hamas and Iran's increasing involvement in the Palestinian arena, including the West Bank, in recent years, I highly doubt whether Iran was significantly involved in Hamas's latest action," he wrote.

However, he added that if the "Israeli response poses a significant challenge to Hamas," it would "oblige Iran to move from the phase of ongoing support and coordination to a more direct involvement."

Israeli Prime Minister Benjamin Netanyahu has already said Israel is "at war" with Hamas and vowed severe retaliation for the attacks. On Monday, Netanyahu said Israel's response to the Hamas attacks would "change the Middle East."

UN ambassador Erdan called the attacks "Israel's 9/11," after which "nothing will be the same."

Damon Golriz, a lecturer and researcher at the Hague University in the Netherlands, told DW that by maintaining a well-crafted doctrine of plausible deniability, Tehran has effectively avoided direct involvement in these conflicts. He added that finding a smoking gun implicating Iran is a political decision that would have devastating consequences.

"It will be a declaration of war between Israel and Iran," he said.