The Axis of Resistance and the regional ramifications of Israel’s war on Gaza

Prior to 7 October 2023, the Middle East was experiencing a period of general political détente, symbolized by the rapprochement between Gulf countries and Iran on one hand,¹ and ongoing normalization efforts with Israel on the other.² This thawing of tensions between regional powerhouses went hand in hand with a notable decline in armed activity attributed to militias and groups linked to the Iran-led Axis of Resistance (AoR) across Yemen, Syria, Iraq, and Iran in 2023 compared to the previous year.³ Away from Israeli ground operations in Palestine and Lebanon, the balance of power within the AoR shifted significantly. The Houthis emerged as a prominent regional force, capitalizing on Hezbollah’s setbacks in Lebanon. Iraqi militias engaged with the US and Israel on a limited scale, and while the Assad regime in Syria largely refrained from direct involvement in the conflict, it was removed definitively from the equation with its rapid collapse in early December in the face of lightning rebel advances. Iran was drawn into its first-ever direct confrontations with Israel, its regional standing diminishing as a result.

In the aftermath of 7 October, the Houthis emerged as the self-proclaimed champions of the Palestinian cause, upsetting the balance of power within the AoR to the detriment of Hezbollah and the Iraqi militias. Yemen’s key geographical position, combined with an asymmetric warfare strategy, provided the Houthis with disproportionate deterrence power.⁴ Since November 2023, the Houthis have disrupted global trade in the Red Sea,⁵ launching over 290 attacks⁶ involving at least 165 ships. Additionally, newly acquired drone and missile technology has enabled them to target Tel Aviv with greater accuracy, prompting the first-ever Israeli airstrikes on Yemeni soil, the latest occurring in September 2024. Domestically, this strategic shift has contributed to a reduction in the group’s frontline activity.

In Iraq, the Islamic Resistance emerged as a new ‘facade’ group for pro-Iran militias in October 2023, claiming responsibility for shelling and drone attacks on US forces in Iraq and Syria. Its activities escalated continuously until January 2024, when a drone attack on a US military outpost in Jordan resulted in the reported deaths of three American soldiers. In the aftermath, Kataib Hizbullah announced a suspension of hostilities.⁷ Since then, the Islamic Resistance has conducted sporadic attacks, primarily drone operations against Israel, which intensified in September following Israel’s launch of Operation Northern Arrows, continued in October, skyrocketed following Israel’s 26 October attack on Iran, and gradually ceased in November.⁸ Alongside the Houthis, the Islamic Resistance claimed dozens of drone and missile attacks against Israel, yet it appeared more vulnerable to the threat of US and Israeli retaliation.

Syria remained a key battleground for Israel and the United States to confront the Lebanese Hezbollah and Iran, enabling retaliation without direct regional escalation. The Assad regime, for its part, shied away from an open confrontation with Israeli forces, yet this neutral stance ultimately did not preserve its hold on power. On 27 November, Hayat Tahrir al-Sham (HTS) and its allies launched a military campaign that resulted in the fall of Syria’s main cities and the end of the Assad family’s 50-year rule. Neither Hezbollah, weakened by the Lebanon conflict and constrained by the recent ceasefire agreement with Tel Aviv, nor Syria’s foreign sponsors, Iran and Russia, came to the rescue of Assad’s crumbling regime during HTS’s flash offensive. Israel instead carried out airstrikes targeting Assad’s military infrastructure and chemical weapons sites. Overall, Israeli airstrikes on Hezbollah and pro-Iran positions in Syria more than doubled in 2024, also involving a series of targeted assassinations of Islamic Revolutionary Guard Corps (IRGC) leaders that culminated in the April 2024 strike on Iran’s embassy in Damascus.⁹

The latter incident triggered Iran’s first direct attack on Israel soon after. Tehran launched over 300 drones and missiles, prompting a low-profile Israeli retaliation. A second escalation occurred in October after Israel assassinated Hamas leader Ismail Haniyeh and Hezbollah’s secretary-general Hassan Nasrallah, leading to Tehran’s launch of more than 180 ballistic missiles toward Israel. In response, the Israeli Air Force targeted Iranian military sites for the first time. These clashes followed a controlled escalation approach, resulting in limited casualties and damage. Yet, the escalation redefined the rules of engagement between Israel and Iran, setting a dangerous historical precedent and pushing the region to the brink of all-out war.

Statements by the United States Biden administration suggesting that the Middle East was at its quietest in a decade stand in stark contrast to the sharp escalation of US regional activity in 2024.¹⁰ Armed activity recorded during the first 11 months of 2024 already surpasses the total for 2023. In fact, Washington was further drawn into the Middle East. American attacks have struck pro-Iran militias in Syria. Aiming to curb Houthi threats in the Red Sea, the US led an international coalition to protect navigation routes, alongside an aerial campaign in Yemen targeting Houthi infrastructure to weaken the group’s missile and drone capabilities. The latter operation involved the highest monthly number of US airstrikes recorded by ACLED since 2018, yet it hardly achieved the goal of degrading Houthi military infrastructure.

What to watch for in 2025

Over the past decade, Iran and the AoR exerted significant deterrence vis-a-vis Israel, with Tehran’s ‘ring of fire’¹¹ and the prospect of coordinated regional strikes seen by Tel Aviv as a sub-nuclear threat.¹² Indeed, Hamas' 7 October attack shook Israel’s sense of invincibility and rallied AoR support from Iran, Lebanon, Iraq, Yemen, and Syria. Yet, this support proved largely symbolic as Iran and Hezbollah sought to avoid full-scale war, and other AoR actors offered limited direct engagement. The strategic balance now favors Tel Aviv, as two of Iran’s key security pillars — regional influence through AoR non-state actors and missile and drone capabilities¹³ — appear strained.

Undoubtedly, Israel’s operations in Lebanon and Gaza have weakened the AoR’s ‘ring of fire,’ reducing the short- to mid-term threat posed by Hamas and Hezbollah. The sudden and unexpected collapse of the Syrian regime has dealt a further blow to Iran’s ‘forward defense’ strategy. Iran has long invested in Syria, with the country serving as a land corridor to deliver logistical and armed support to Hezbollah.¹⁴ While Assad’s fall represents a major strategic setback, Tehran has already signaled the will to maintain relations with Syria¹⁵ in an effort to preserve its foothold in the region. Israel, on the other hand, seized a buffer zone in the Golan Heights, and it is likely to continue its airstrikes to curb Iranian influence at its borders. Lastly, Syria’s new rulers, once united in opposition to Assad, now face a new reality that could fuel further internal fragmentation and instability, impacting the broader Middle East.

The situation in Iraq is even more uncertain. Israel’s 26 October attack on Iran drew unanimous condemnation from Shiite Iraqi actors, yet deep internal fractures persist between them. Intra-Shiite violence resurged after the December 2023 provincial elections, and potential early elections with the Sadrists may threaten Prime Minister Muhammad Shia al-Sudani’s position.¹⁶ In 2024, Sudani initiated a rapprochement with Turkey and agreed with Washington on a phased US troop withdrawal while pledging to strengthen the role of the Iraqi forces against the Islamic State (IS).¹⁷ However, the resurgence of IS and increased attacks by pro-Iran militias against Israel and the US are straining the government,¹⁸ and Israel has threatened strikes if attacks originate from Iraqi soil.¹⁹

The Houthis’ support for Palestine has won them consensus regionally and across Yemeni political factions, boosting recruitment. The group has consolidated its grip on civil society and strengthened its ranks in Yemen by exploiting the relative calm on domestic frontlines. A resumption of hostilities — especially around Marib and the West Coast — remains a potential leverage point in negotiations with regional and international actors. The Houthis pledged to reassess Red Sea operations if Israeli actions in Gaza cease.²⁰ A temporary halt of the attacks is probable in the event of a ceasefire, and Saudi Arabia — eager to exit the Yemen war and pressured by Houthi threats to oil infrastructure²¹ — may resume discussions on the United Nations peace roadmap.²² Despite the group’s pro-Palestine rhetoric, drone and missile attacks in the Red Sea primarily aim to maximize Houthi power in Yemen and will remain a long-term threat.

With the AoR weakening and missile attacks on Israel proving less effective, Iran’s deterrence appears diminished and may prompt a strategic shift. From the start of the Gaza crisis, Tehran has signaled a desire to stay out of the conflict, quickly de-escalating tensions after each round of attacks. Additionally, President Masoud Pezeshkian expressed a willingness to engage the West to lift sanctions.²³ Tehran will likely seek to end direct confrontations with Israel and return to indirect confrontations through AoR members. Meanwhile, it may be tempted to go all-in on developing a nuclear deterrent to strengthen its position in future negotiations with the US administration.²⁴

Conversely, Israel may seek to capitalize on its military advantage to strengthen its deterrence posture, potentially through new strikes on Iran’s nuclear infrastructure, targeting militia activity in Syria and Iraq, and attempting to decapitate the Houthi leadership in Yemen. Implementing these threats will also depend on the stance of the new US administration. Donald Trump’s victory in the recent presidential elections adds a layer of unpredictability to the Middle Eastern equation despite his unwavering support for Israel and an arguably isolationist stance.²⁵

Trump’s immediate priority will likely be ending the conflicts in Lebanon and Palestine, with little focus on long-term regional strategy and an effort to decouple the Palestinian file from the broader Middle East agenda. He may reinstate a ‘maximum pressure’ policy on Iran,²⁶ maintain US support for counter-terrorism and Israeli operations in Syria, and bolster local forces in Iraq while pursuing a gradual drawdown of troops. Trump’s transactional ties with Gulf countries — centered on security, economic deals, and normalization with Israel²⁷ — will probably dictate his approach toward Yemen. This will entail curbing the Houthi threat in the Red Sea through sanctions, international coordination, and support for regional partners, particularly those backed by the United Arab Emirates.