Iran might strike Israel with up to 1,000 ballistic missiles if a planned Israeli retaliatory attack on the Islamic Republic results in high civilian casualties and widespread destruction, according to reports.
Four officials, including two from the Iranian Revolutionary Guard Corps (IRGC), told The New York Times that Israel can expect a massive retaliation by Tehran if its long-expected strikes on the country inflict heavy damage to the country's vital energy infrastructure.
This follows Iran's retaliatory missile strikes on Israel on 1 October, which caused minimal damage to military sites and no civilian deaths, and followed the killing of Hassan Nasrallah and other Tehran-linked figures in the region, hiking tensions between the two countries.
In addition to a barrage of a thousand missiles, Iran might also target Gulf shipping, escalate attacks from Tehran's regional proxy force, and possibly target regional energy facilities, likely to cause oil prices to skyrocket.
If Israel limits its strikes to military facilities with minimal damage, then Iran might not respond at all, the sources added.
Tehran officials have made public statements directed at Israel, warning it not to overstep the mark, after Tel Aviv vowed to respond to Iran's 1 October drone and missile strike - the biggest since the war on Gaza and Lebanon began in October 2023.
It has also made intense diplomatic moves to urge the US to restrain its ally Israel, amid threats to target Tehran's energy infrastructure, which could have devastating consequences for the oil exporter.
"In the event of an Israeli attack, the shape of our response will be proportionate and calculated," Iran Foreign Minister Abbas Araghchi said at this week's BRICS summit in Russia this week.
The sources told The New York Times that the Iranian military is preparing for unrest within its borders with possible insurrections among minority groups or attacks by the Islamic State group.
Israel is reportedly adamant that a military response to 1 October strikes will happen, as occurred when Tehran launched missile strikes on Israel on 13 April following the killing of a senior IRGC general at an Iranian diplomatic compound in Damascus two weeks earlier.
The question is, how broad the military action will be and what role Washington might play with the US deploying THAAD anti-missile batteries to Israel, indicating that the response could be major.
Israel is said to have delayed its response after details of a planned attack on Iran were leaked from the US, the security breach possibly hinting at some concerns in Washington about the response on the table.
Defence Minister Yoav Gallant confirmed this week that an attack from Israel was coming.
"In my conversation with them I emphasised - after we attack Iran, everyone will understand your might, the process of preparation and training - any enemy that tries to harm the state of Israel will pay a heavy price,” he wrote on X after speaking with US officials.
Israel launched a devastating war on Gaza following the 7 October attacks, and escalated its military actions in Lebanon this month, leading to tens of thousands of civilian deaths.