Hamas is an idea and you don’t kill an idea. Or so they keep telling us. These are the words of the European Union’s foreign policy chief, Josep Borrell, not your average student activist.

Borrell’s line of argument is, of course, flawed from the very offset. Nazism in Europe in the 1940s simply could not have been defeated without a military campaign that dismantled Hitler’s Third Reich.

The same is true of Hamas in Gaza. The death of Yahya Sinwar, the group’s leader and mastermind behind the October 7 terrorist attacks, brings us one step closer to the unravelling of the entity that nurtures Islamist extremism in Palestinian territories.

But in killing Sinwar, Israel has not just inflicted a major setback on Hamas. The death of the October 7 mastermind lands another colossal blow to Hamas’ main patron, the Islamist regime in Iran, in what appears now to be a weekly occurrence for Tehran.

Of course, the same “you can’t kill an idea” crowd will be quick to argue that Hamas is an organisation, not a person, and therefore Sinwar can be replaced.

Let’s not forget this was the same argument used after the deaths of other terrorists such as Hezbollah leader Hassan Nasrallah and Sinwar’s colleague in Qatar, Ismail Haniyeh.

But what they underestimate – or simply fail to understand – is that the terrorist militia alliance known as the “Axis of Resistance”, which is commanded by the Islamic Revolutionary Guard Corps (IRGC), the Iranian regime’s ideological paramilitary organisation, is an extremely personalistic system that functions on close patron-client relationships developed over decades.

As with those of Nasrallah and Haniyeh, Sinwar’s death significantly weakens the institutional memory and capabilities of both the IRGC and its terror militia network.

This is especially the case for Sinwar, as he was known as Tehran’s man in Gaza who had a close, longstanding relationship with Iran’s regime, having personally met supreme leader Ayatollah Ali Khamenei. In fact, this relationship was so close that after Haniyeh’s death in Tehran, many conspiracy theories emerged that Khamenei had deliberately “sold out” Haniyeh to replace him with “Tehran’s man”.

But while Sinwar’s death is undoubtedly a major loss for Khamenei and the IRGC, it is unlikely to draw a major retaliation from Tehran. Khamenei is already feeling overwhelmed in the ongoing confrontation with Israel and, as a result, he needs to pick and choose his battles.

When Nasrallah was killed, the ayatollah and the IRGC could not sit back in silence due to the fact that he was the leader of the regime’s most important proxy. Hezbollah was created by the IRGC and Khamenei had an almost father-son relationship with the late Nasrallah.

But the Sunni group Hamas doesn’t enjoy the same value as Hezbollah for Khamenei. As a consequence, the ayatollah will have no qualms treating Sinwar and the rest of the Hamas terrorists as cannon fodder for the Iranian regime’s war on Israel. In fact, unlike Nasrallah and Haniyeh, Khamenei has not vowed to “avenge” the blood of Sinwar.

For decades, western policymakers were insistent that the Iranian regime’s terrorist militia network was a bitter reality that had to be accepted, not challenged. But in the space of a few months, Israel has not only exposed its major vulnerabilities but may have started the unravelling of the once “impenetrable” Axis of Resistance. Critics will argue that elimination of Hamas and Hezbollah’s leadership and the degradation of its capabilities will simply see these groups transitioning into guerrilla warfare and insurgency mode.

But this itself would indicate the beginning of the end for Khamenei’s regional Islamist imperialist project. It took more than four decades for the IRGC to transition these militant Islamist groups from insurgent status to “mainstream” forces. A forced reversal to insurgency mode could in many ways mean back to square one for Khamenei.

Today, however, the Middle East is completely different and, due to the Abraham Accords, Israel and Arab states such as Saudi Arabia are unlikely to have much difficulty working together to prevent Khamenei from rebuilding his terrorist militias, not least in places such as Lebanon.

Of course the fight is still not over – and it is important not to get too far ahead of ourselves. But one thing is for certain: the Middle East under the domination of the IRGC and its militia network no longer looks like a bitter reality that simply must be accepted.

Because of Israel’s actions, a golden opportunity has emerged to challenge Khamenei’s Islamist imperialistic project once and for all. This thought alone should wake up policymakers in the West, many of whom appear to have allowed their innate hostility towards Israel to blind them to this defining moment.

Kasra Aarabi is the director for IRGC Research at United Against Nuclear Iran (UANI)