Iran’s response to Israel looms. What are the possible scenarios?

With tension in the Middle East at its highest since October 7, how did we get here and what could happen next?

The assassination of Hamas political chief Ismail Haniyeh in Tehran, along with the killing of leading Hezbollah figure Fuad Shukr in Beirut, has sent shockwaves throughout the Middle East, and the feeling that the Iranians are likely to respond with an attack on Israel that could start an all-out regional war.

Israel is widely believed to have carried out Haniyeh’s killing, and claimed the assassination of Shukr. Following on from months of devastating attacks on Gaza, where almost 40,000 Palestinians have been killed, and previous escalations against both Iran and its ally Hezbollah in Lebanon, there is apprehension over what comes next, with the fear that Lebanon in particular could be at risk of attack in the case of any extended conflict.

It has now been almost a week since both Haniyeh and Shukr were killed, but no major attack on Israel has yet been conducted, with diplomats scurrying around the region in an effort to stave off any escalation.

The Iranians have insisted they will respond, with Ministry of Foreign Affairs spokesperson Nasser Kanaani saying on Monday that regional stability could only come from “punishing the aggressor and creating deterrence against the adventurism of the Zionist regime [Israel]”.

The question now is – what shape will this response take? Will it be a measured effort calculated to avoid a regional war – much like the last time Iran felt like it had to respond to an Israeli attack in April? Or will Iran’s leaders believe that the latest attacks require a more forceful response, even if it risks a wider conflict?