Hamas Struggles to Replenish Leadership as Israel's Campaign Kills October 7 Operatives

In late May 2026, Israel killed Mohammed Odeh, the newly appointed commander of Hamas's Izz ad-Din al-Qassam Brigades, just 11 days after he assumed the role [1]. Odeh had replaced Izz al-Din al-Haddad, who was himself killed by an Israeli strike earlier that month [2]. The rapid-fire eliminations marked the latest chapter in a campaign that has now removed virtually every senior Hamas figure connected to the October 7, 2023 massacre — a systematic targeting effort without clear precedent in the history of counterterrorism.

But the speed at which Hamas appointed and lost two military chiefs in less than two weeks also illustrates a different reality: the organization keeps naming replacements, even as those replacements are killed within days. The question facing Israeli strategists, regional governments, and Palestinian civilians living under the wreckage is whether this campaign has genuinely hollowed out Hamas or merely accelerated a cycle of martyrdom and succession that the group has survived before.

The Toll: A Near-Complete Decapitation

The scale of Israel's targeting campaign since October 7 is stark. The roster of confirmed kills includes the most senior echelon of both Hamas's political and military leadership [3][4]:

• Saleh al-Arouri, deputy head of Hamas's political bureau and a founder of its military wing, killed in a drone strike in Beirut in January 2024 [3].
• Marwan Issa, deputy commander of the al-Qassam Brigades, killed in an Israeli strike in March 2024 [3].
• Ismail Haniyeh, chairman of Hamas's political bureau, killed by a concealed bomb in a Tehran guesthouse on July 31, 2024 [3].
• Mohammed Deif, longtime commander of the al-Qassam Brigades and a principal architect of October 7, killed in a strike in July 2024 [3].
• Yahya Sinwar, Hamas's overall leader and the chief planner of the October 7 attacks, killed by Israeli forces in Rafah in October 2024 [4].
• Mohammed Sinwar, Yahya's brother, who led the al-Qassam Brigades from July 2024 until his death in May 2025 [4].
• Ra'ad Sa'ad, senior military commander, killed in December 2025 [1].
• Izz al-Din al-Haddad and Mohammed Odeh, successive al-Qassam Brigades commanders, both killed in May 2026 [1][2].

Source: Times of Israel / Multiple Sources

Data as of May 28, 2026CSV

According to Israeli military assessments and multiple news reports, only one member of Hamas's core military council from the October 7 era remains alive: Imad Aqel, the head of the home front staff in Hamas's military wing [5]. Aqel, born in 1971 in the Jabalia refugee camp, is responsible for logistics, infrastructure, weapons production, and supply. Unlike figures such as Sinwar or Deif, Aqel has maintained a low public profile, which analysts say has helped him survive multiple assassination attempts [5].

Historical Precedent: The Yassin Test

Hamas has faced leadership decapitation before. In March 2004, Israel assassinated Sheikh Ahmed Yassin, the group's co-founder and spiritual leader, in a helicopter strike in Gaza City [6]. Hamas named hard-liner Abdel Aziz al-Rantisi as his replacement within 24 hours [7]. When Israel killed al-Rantisi 26 days later, the external leadership under Khaled Mashal — already operating from Damascus — assumed overall control [6][7].

The 2004 transition is instructive for two reasons. First, the speed of succession was measured in hours, not weeks. Second, the replacements were not unknown figures elevated from obscurity; they were long-serving leaders who had been running operations alongside Yassin for years [7]. The killing of the titular head did not disrupt organizational continuity because the real decision-making apparatus was distributed.

The current campaign differs in scope. Israel has not killed one or two leaders; it has systematically eliminated nearly the entire senior military and political command structure over 31 months. The question is whether this quantitative difference produces a qualitative change in Hamas's ability to function — or whether the group's cellular, decentralized structure makes it resistant to even this level of attrition.

What the Academic Literature Says

The scholarly debate on leadership decapitation is divided. A widely cited study by Jenna Jordan, published in International Security through MIT Press, analyzed 298 instances of leadership targeting across multiple organizations and found that "decapitation does not increase the likelihood of organizational collapse" [8]. Jordan's research showed that older, larger, and religiously motivated organizations — categories that include Hamas — were the most resilient to leadership removal.

By contrast, Patrick Johnston's research, published through the Belfer Center at Harvard, found that successful leadership targeting did correlate with shorter organizational lifespans and reduced operational capacity, but only under specific conditions: when combined with broader pressure on financing, recruitment, and territorial control [9].

A RAND Corporation analysis concluded that targeted killings can "gradually erode a terrorist group's leadership," but cautioned that the strategy works best as one element of a broader campaign, not as a standalone approach [10]. The Georgetown Security Studies Review raised a specific concern: successful killings of senior leaders tend to make organizations "less discriminate in target selection," because lower-level commanders who fill the void often have weaker norms against civilian targeting [11].

The evidence, in sum, does not support a simple narrative in either direction. Decapitation can degrade organizations, but it rarely destroys them. And it carries the risk of producing successors who are more violent, less politically sophisticated, and harder to negotiate with than the leaders they replace.

The Fighter Question: Degraded but Not Destroyed

Israeli intelligence assessments, reported across multiple outlets, estimate that approximately 20,000 Hamas fighters were killed during the war, reducing the group's pre-war strength of roughly 30,000 to a current force of between 10,000 and 25,000 — a range that reflects genuine uncertainty about new recruitment [12][13].

Source: Israeli Intelligence Assessments / Media Line

Data as of May 28, 2026CSV

The remaining fighters are described as lower quality than their predecessors, with Israeli officials noting that new recruits lack the training and operational experience of pre-war cadres [13]. Israeli strikes have also destroyed an estimated 90% of Hamas's rocket arsenal [12].

However, several indicators suggest the organization retains meaningful capacity. Armed Hamas operatives have been observed patrolling streets, clashing with rival factions, and carrying out public executions [14]. An estimated 70% to 80% of Hamas's tunnel network remains intact, with large sections unmapped by the IDF [12]. And the group continues to claim ceasefire violations and conduct limited attacks against Israeli forces [15].

NBC News reported in mid-2025 that Hamas was "diminished but not destroyed," with the group reasserting itself in areas where the IDF had previously conducted clearing operations [14]. This pattern — of areas being cleared and then reverting to Hamas influence — is consistent with an insurgency that has lost conventional military capacity but retains guerrilla and governance functions.

The Money Pipeline: Disrupted but Not Severed

Before October 7, U.S. and Israeli officials estimated that Iran provided Hamas $70 million to $100 million annually [16]. Qatar had separately channeled hundreds of millions of dollars to Gaza, ostensibly for civilian purposes, though Israeli intelligence later assessed that Hamas diverted at least $4 million monthly from Qatari funds to its military wing beginning in March 2022 [17].

The financial landscape shifted after October 7. The United States and Qatar reimposed restrictions on approximately $6 billion in frozen Iranian oil revenues held in Qatari banks, which had been released as part of a September 2023 prisoner exchange [18]. International sanctions pressure intensified, and several Hamas-linked financial networks were disrupted.

But the loss of operational leaders in Gaza does not necessarily sever money flows. Hamas's financial infrastructure has long been managed from outside the Strip. Muhammad Darwish, the current head of the General Shura Council, has historically managed Hamas's investment portfolio from abroad [19]. The organization maintains financial networks across Turkey, Malaysia, Sudan, and other countries. The killing of military commanders in Gaza disrupts tactical execution — how money is spent on weapons, tunnels, and operations — but not the fundraising and investment apparatus that generates revenue.

Iran's commitment to Hamas appears to have survived the war, though the mechanism of support has been complicated by the degradation of the Iran-Syria-Hezbollah supply corridor following Israel's separate campaign against Hezbollah in late 2024.

The Succession Race: Hayya vs. Mashal

With most of its Gaza-based leadership dead, Hamas's political future is being shaped by figures operating from Doha, Istanbul, and Beirut. The two leading candidates to become the next chairman of Hamas's political bureau represent starkly different visions [19][20].

Khalil al-Hayya, head of Hamas's political bureau in Gaza and a key negotiator during ceasefire talks, is considered the frontrunner. Al-Hayya enjoys backing from both the Shura Council and the al-Qassam Brigades [20]. His ascension would signal continuity with the Iranian-aligned military strategy, emphasizing Gaza as one front in a broader regional conflict [19].

Khaled Mashal, who led Hamas's political bureau from 2004 to 2017, represents a more pragmatic approach. Mashal has signaled openness to diplomatic arrangements and greater distance from Iran's "axis of resistance" [19][20].

A potential compromise candidate is Muhammad Darwish (Abu Omar Hassan), who controls the organization's finances and currently chairs the interim leadership council formed after Haniyeh's death. Darwish maintains relationships with both Iran and Turkey, making him acceptable to multiple factions [19].

The elections, originally scheduled for early January 2026, were postponed due to Hamas's participation in Phase Two negotiations of the ceasefire framework [20]. The delay itself reveals a tension: Hamas cannot hold internal elections while simultaneously negotiating its political future with external mediators.

The ideological trajectory of whichever leader emerges matters. If the academic literature is correct that decapitation campaigns tend to empower more hardline successors, the elimination of relatively pragmatic figures like Haniyeh could push the organization toward leaders with less interest in political compromise.

Governance Vacuum: Who Runs Gaza?

The degradation of Hamas's leadership has coincided with efforts to establish alternative governance structures in Gaza. Under the terms of the October 2025 ceasefire, Hamas agreed in principle to transfer civilian administration to the National Committee for the Administration of Gaza (NCAG), a technocratic body endorsed by UN Security Council Resolution 2803 [21].

The NCAG, led by chief commissioner Ali Shaath, formally began work in Egypt in January 2026 [21]. However, its actual authority in Gaza remains minimal. Israel has blocked committee members from entering the territory, and Hamas retains de facto security control over much of the Strip [22].

This creates a governance paradox. Hamas recognized that overt control of Gaza would deter international reconstruction funding and potentially provoke civilian unrest [22]. But the alternative — a technocratic committee with no security apparatus, no territorial access, and no enforcement capacity — is a governance structure in name only.

In practice, Hamas's mid-level administrative cadre continues to perform many civil functions: distributing aid, managing local disputes, and maintaining a semblance of order in areas where the IDF is not present [14]. The simultaneous degradation of this cadre alongside the military leadership creates a secondary crisis: even if the military wing is weakened, the loss of administrators who keep civilian infrastructure functioning produces humanitarian consequences that military planners may not have anticipated.

The Washington Institute for Near East Policy has described Hamas's continued governance role as "shadow governance," noting that the group has historically derived legitimacy not just from armed resistance but from its provision of social services, education, and dispute resolution [22].

The Central Paradox

Israel has achieved something operationally extraordinary: the near-total elimination of the command structure that planned and executed the deadliest attack on Israeli civilians in the country's history. Every senior military planner of October 7 except one is confirmed dead. The political bureau has been decapitated twice over.

But the strategic question remains unresolved. Hamas's cellular structure, its external leadership nodes, its intact tunnel network, its continued recruitment of fighters — albeit lower-quality ones — and its embedded governance role in Gaza all suggest an organization that has been severely damaged but not destroyed.

The academic evidence on decapitation strategies suggests that killing leaders works best when combined with efforts to cut financing, offer political alternatives, and address the underlying conditions that drive recruitment. Israel's campaign has been heavily weighted toward the first element — the killing — while the others remain incomplete. Qatar and Iran's financial support has been disrupted but not eliminated. No credible alternative governance structure has been established. And the conditions in Gaza — massive destruction, displacement, and civilian casualties — may be generating the very grievances that fuel Hamas's next generation of recruits.

The killing of Mohammed Odeh 11 days after his appointment encapsulates the paradox. It demonstrated Israel's extraordinary intelligence penetration of Hamas. It also demonstrated that Hamas had someone ready to appoint, even knowing that appointment was likely a death sentence. As long as both of those things remain true, the campaign of targeted killing will continue — and so will the debate about whether it is working.