How will Israel respond to Iran’s missile attack, and why is Israel in Lebanon?

Tensions in the Middle East have escalated sharply once more amid retaliatory threats exchanged by Israel and Iran, after Tehran fired a barrage of ballistic missiles at Tel Aviv late Tuesday (Oct 1).
Israel has vowed Iran will pay for its “big mistake”, with Prime Minister Benjamin Netanyahu warning: “Whoever attacks us, we attack them.”
Tehran doubled down by threatening painful consequences if Israel reacts, with its Revolutionary Guards promising to carry out “crushing attacks”.
Analysts said this is the most “risky and volatile” point in the conflict yet, with Israel and Iran on the brink of direct military exchange, as the region braces for an increasing possibility of a wider war.
World leaders have urged restraint and to prioritise the protection of civilians.
Observers said they are almost certain of Israeli retaliation, but the severity of its response will determine if the conflict escalates.
“It’s incredibly unlikely that Israel will not respond to those Iranian missiles,” said Jessica Genauer, an international relations senior lecturer at Flinders University.
“While that’s not a situation that Israel or Iran … or other international actors want to see, it’s very hard to see how either Iran or Israel will de-escalate from this point.”
Ryan Bohl, a senior Middle East analyst at RANE network, said Israel is likely to be looking at a more substantial reprisal than it did in April, when it hit an Iranian air base with a missile in response to a similar attack.
This time, Israel could even target Iran’s nuclear programme, energy facilities, or missile and drone production capabilities, he said.
However, he added that if Israel shows restraint in its retaliation, tensions could somewhat simmer down.
“If the attacks are considered insubstantial to Iran, Tehran may call the Israelis’ counterattack a failure, and then climb off the escalation ladder for the time being,” Bohl told CNA.
“But if the attacks are seen as substantial, if they interrupt oil exports or cause national humiliation for Iran by, say, destroying sensitive nuclear sites, then Iran is likely to consider its next strike against Israel.”
Iran is in a “very difficult position” of being torn between not wanting to escalate the conflict with Israel and showing support to its proxies, Genauer said.
Additionally, Tehran is likely shocked at the extent of Israel’s intelligence network that has breached Hezbollah, and the fact that Israel could take out the Iran-backed Lebanese militant group’s top leaders, she noted.
“Iran will be very nervous right now … and wondering what kind of intelligence Israel could have on the Iranian leadership and its military,” Genauer told CNA938’s Asia First programme.
Iran rained more than 180 ballistic missiles on Israel on Tuesday, saying the attack was in response to the killings of Iran-backed militant leaders. 
But analysts said it is “no coincidence” the attack was carried out just after Israel’s military launched ground operations targeting Hezbollah in south Lebanon on Monday.
“(Iran’s missile attack) was a warning to the Israelis that Iran is prepared to intervene in Israel’s military campaign against Hezbollah,” said Bohl.
Israel said most missiles were intercepted by its air defences or allies. No deaths or injuries were reported.
Analysts said Israel is moving quickly to severely incapacitate Hezbollah, after killing the group’s leader Hassan Nasrallah in air strikes in Beirut last Friday.
Gerald Feierstein, a distinguished senior fellow at Washington-based think tank the Middle East Institute, said Israel is likely trying to drive Hezbollah from southern Lebanon to beyond the Litani River, located about 30km north of the Israel-Lebanon border.
“If Hezbollah is not able to operate south of the Litani, it wouldn’t have the capability to strike directly at Israeli targets,” he said.
Hezbollah has been launching near-daily rockets on northern Israel since Oct 8 last year in solidarity with Hamas, a day after the latter’s incursion into Israel ignited the current war.
Feierstein added: “It looks like the Israelis are trying to implement UN Security Council resolution 1701 on the ground by their military operations.”
He was referring to the United Nations resolution that ended the month-long war between Israel and Hezbollah in 2006, which would see Israel’s withdrawal from southern Lebanon and the deployment of Lebanese army and UN peacekeepers south of the Litani River.
The Lebanese government in recent days said it is ready to fully implement the 2006 resolution and deploy its army south of the river to stop war with Israel.
“Whether the situation escalates more broadly in the region will very much depend on the extent of Israel’s operation in Lebanon. A lengthy operation will increase that likelihood,” Genauer said.
She pointed to the war in Gaza, which was expected to be relatively short but will mark a year of bloodshed next week. The conflict has since expanded to Lebanon amid looming threat from Iran.
She added that although Hezbollah has been thrown into disarray, it still has tens of thousands of trained fighters, and Israel does not have the military capability to fight on two fronts.
Genauer warned that should Israel and Iran come into conflict, the situation may become volatile and at a “cost that no one will want to contemplate”, as the United States could be drawn into the fray.
Feierstein said there are likely indirect, behind-the-scenes discussions between Washington and Tehran – the two have had no formal diplomatic relations since 1980 – to limit the escalation, as neither wants an expansion of the conflict.
Still, the US has shown “little inclination to use its leverage” to restrain Israel, said Bohl.
“Israel has assessed – seemingly correctly, least for the moment – that it can carry out hawkish missions against their adversaries without triggering a region-wide war, and without causing a diplomatic crisis with the US,” he told CNA.
Analysts have repeatedly emphasised a Gaza ceasefire is still the elusive key to ending the conflict.
“At the core of this, this is still all about Gaza,” said Bohl.
“Without a resolution on Gaza, all of these secondary and tertiary conflicts will continue to have fuel for their fire.”
While the US remains an ally, Washington may be forced to take stronger action to rein in Israel if the conflict expands to cause geopolitical shock and affect oil prices, especially as the US election nears, said Bohl.
“If Israel is seen as a non-constructive partner, eventually, Washington – whether under Biden, Harris or Trump – will conclude that some sort of step needs to be taken to restrain Israeli behaviour,” he added.