IRANIAN leader Ebrahim Rasi has vowed a deadly airstrike on its consulate in Syria "will not go answered".
At least seven officers including one of Tehran's top generals were killed after suspected Israeli warplanes bombed the consulate in the Syrian capital Damascus.
Israel has repeatedly targeted installations in Syria and those of its proxies.
But Monday's attack was the first time it apparently hit the vast embassy compound itself.
Iranian state television branded the strike an "assassination attempt"; against its ambassador, who survived.
Tehran has now insisted it is plotting a retaliation after its Supreme National Security Council, a key decision-making body, met late Monday.
President Ebrahim Rasi labelled the attack a "cowardly crime" as he pointed the finger of blame at Israel.
He said: "Having failed to destroy the will of the resistance front, the Zionist regime has put blind assassinations back on its agenda to save itself.
"It must know that it will never achieve its goals and that this cowardly crime will not go unanswered."
It has left the Middle East on a knife-edge amid fears of an all-out war in the region.
Dr Alan Mendoza - executive director of think tank Henry Jackson Society - warned Iran could use one of its proxies to retaliate.
He told The Sun: "Iran has little choice but to promise revenge seeing as it has been caught with its pants down in a major intelligence breach allowing Israel to kill its senior terrorist commanders.
"This does not necessarily mean a response will be immediate.
"We have been living in a tit-for-tat environment in the Middle East for several years. Israel will probably be targeted through Iranian proxy groups like Hezbollah, or through global terrorism against Israeli or Jewish targets.
"The danger lies in Hezbollah crossing a red line in any response that could provoke a war with Israel, which is already a possibility given activity on the Lebanese border."
By Jerome Starkey, The Sun's Defence Editor
FEARS that the Middle East could explode into all-out war are ratcheting up today after Iran vowed vengeance for a deadly Israeli missile strike on its embassy in Damascus, the capital of Syria.
At least 11 people were killed when a consular annex was reduced to rubble by strikes which Iran says were carried out by Israeli F-35 fighter jets.
Now among those 11 killed were two top Iranian generals, Brigadier Mohammed Reza Zahidi, who we understand commanded Iran's Revolutionary Guard in Syria and neighbouring Iraq, and Brigadier Mohammed Haji Rahimi.
Also among the dead is a representative of the Hezbollah terrorist group Hussein Yusuf.
Both Iran and Hezbollah have vowed vengeance, with Iran's president Ebrahim Raisi saying this strike will not go unanswered.
The suggestion is that perhaps Israel has crossed a threshold with a strike on an embassy.
Embassies are sovereign soil of the nations they belong to, so this was a strike on sovereign Iranian soil in Syria and in one sense it is an escalation and the concerns that this could spiral out are in many ways well founded.
Interestingly today we've heard reports in the local media in Syria and in the region that America appears to be distancing itself from this strike, officials saying they had no advanced knowledge.
It would appear that the reason for this missile strike was the meeting between these Revolutionary Guard commanders and the representatives of Hezbollah.
We will now have to wait and see how Iran chooses to take its revenge.
Now of course, if you are an Israeli diplomat living abroad, then you may well think that you are now more of a target.
Because Israel has targeted an Iranian embassy, we may expect to see the possibility that Iran may target Israeli diplomats or missions around the world.
And we have just seen in the last few days suspected Iranian agents attacking an Iranian journalist here in London.
Tehran is showing, perhaps by this stabbing, that it maintains the ability and the capability to attack people it sees as enemies of the regime around the world.
Some context that we understand that Tehran employs criminal proxies to carry out that sort of dirty work doesn't necessarily have the same sort of sophisticated overseas operations that we might expect of other hostile actors like Russia.
But nonetheless, I think in the wake of what happened in Damascus on Monday, combined with what's been happening across the region in recent months, there is concern and anxiety to see how Iran responds and what that will elicit from Israel.
Iran has been left furious as one of its top generals Gen. Mohammad Reza Zahedi, who led the elite Quds Force in Lebanon and Syria, was killed.
He died alongside his deputy Gen. Mohammad Hadi Hajriahimi, and five other officers.
Hezbollah said Tuesday that Zahedi played a crucial role in helping develop and advance the work of the group in Lebanon.
Zahedi was sanctioned by the UK and US.
The US Treasury said he acted as a "liaison" to Hezbollah and Syrian intelligence services.
It is understood he was charged with guaranteeing weapons shipments to Hezbollah.
Hezbollah said: "This crime will certainly not pass without the enemy receiving punishment and revenge."
It is not clear whether Iran will respond itself, risking a dangerous confrontation with Israel and its ally the US, or if it will continue to rely on proxies, including Hezbollah militia and Yemen's Houthi rebels.
Since the outbreak of the war in Gaza nearly six months ago, those proxies have stepped up attacks, leading to near-daily cross-border exchanges between Hezbollah and Israel.
Frequent Houthi attacks have also plagued Red Sea shipping.
Hamas, which rules Gaza and attacked Israel on October 7, is also backed by Iran.
Israel, which rarely acknowledges strikes against Iranian targets, said it had no comment on the latest attack in Syria.
Israel has grown increasingly impatient with the daily exchanges of fire with Hezbollah, which have escalated in recent days, and warned of the possibility of a full-fledged war.
Houthi rebels have also been launching long-range missiles toward Israel, including on Monday.
There's been an ongoing conflict between Israel (left) and Iran (right).
In 1947, Iran was among 13 countries that voted against the United Nations Partition Plan for the British Mandate of Palestine.
Two years later, Iran also voted against Israel's admission to the United Nations.
After the 1979 Islamic Revolution, Iran severed all diplomatic and commercial ties with Israel, and its theocratic government does not recognize the legitimacy of Israel as a state.
The turn from cold peace to open hostility began in the early 1990s, shortly after the collapse of the Soviet Union and the defeat of Iraq in the Gulf War, after which relative power in the Middle East shifted to Iran and Israel.
CONFLICT 'HEATS UP'
The conflict escalated in the early 1990s, as Yitzhak Rabin's government adopted a more aggressive posture on Iran.
Rhetorical conflict heated up during the presidency of Mahmoud Ahmadinejad, who made inflammatory statements against Israel.
Other factors that have contributed to the escalation of bilateral tensions include Iran's development of nuclear technology relative to Israel's long-stated Begin Doctrine, Iran's funding of Islamist groups such as Hezbollah, Palestinian Islamic Jihad and Hamas, as well as alleged involvement in terrorist attacks such as the 1992 attack on Israeli embassy in Buenos Aires and the 1994 AMIA bombing, and Israel's alleged support for militant groups such as the People's Mujahedin of Iran and Jundallah as well as alleged covert Israeli operations in Iran including multiple assassinations and bombings.
'COMPLEX AND ONGOING'
Since 1985, Iran and Israel have been engaged in an ongoing proxy conflict that has greatly affected the geopolitics of the Middle East, and has included direct military confrontations between Iranian and Israeli organizations, such as in the 2006 Lebanon War.
The conflict has played out in various ways, including through support for opposing factions in conflicts in Syria and Yemen.
Iran has provided support to the Syrian government, while Israel has supported opposition groups.
In Yemen, Iran has provided support to the Houthi rebels, while Israel has provided support to the Saudi-led coalition fighting the rebels.
The conflict has also involved cyber attacks and sabotage against each other's infrastructure, including attacks on nuclear facilities and oil tankers.
Overall, the Iran-Israel proxy conflict is a complex and ongoing conflict that has had a significant impact on the political and security dynamics of the Middle East.
INSIDE THE WAR
In the Israeli–Lebanese conflict, Iran has supported Lebanese Shia militias, most notably Hezbollah. In the Israeli-Palestinian conflict, Iran has backed Palestinian groups such as Hamas.
Israel has supported Iranian rebels, such as the People's Mujahedin of Iran, conducted airstrikes against Iranian allies in Syria and assassinated Iranian nuclear scientists. In 2018 Israeli forces directly attacked Iranian forces in Syria.
Iranian Islamists have long championed the Palestinian people, whom they perceive as "oppressed".
Scholars believe that by supporting the Palestinians, Iran seeks greater acceptance among Sunnis and Arabs, both of whom dominate the Middle East.
Ideologically, Iran seeks to replace Israel with a one-state solution and has predicted Israel's demise. Israel sees Iran as an existential threat, and accuses its regime of harboring genocidal intentions.
Consequently, Israel has sought sanctions and military action against Iran to stop it from acquiring nuclear weapons.
