Hamas members are “ants”, Yasser Arafat declared during a speech in Yemen in 1990. While the future Palestinian president invoked the aspersion to declare Fatah’s military strength over its newly established Islamist rival, it became clear over time that Fatah was not up to the fight. At each stage, Hamas has emerged scarred but triumphant from attempted defeat. Israel’s experience in managing the group has proven eerily similar. 

Almost a year after Hamas’ attack on Israel, the deadliest single day for world Jewry since the Holocaust, the war in Gaza shows few signs of abating. The intervening months have been marked by widespread death, destruction, civilian displacement, hunger, and disease. And yet Israel’s key identified aim for its Gaza offensive—the complete elimination of Hamas—remains an elusive prospect. As Gaza lies in ruins, Hamas remains intractable, a deadly guerrilla force that is still in de facto control of large swaths of the Gaza Strip. Hamas’ ongoing resilience is a function of both bureaucratic and ideological factors that have historically proven to challenge Israeli counterterrorism efforts and defy easy solutions.

Leadership Decapitations and Targeted Killings: A Tried and Tested Tactic
Leadership decapitations, also known as targeted killings, have featured prominently among Israel’s tried and tested counterterrorism tactics, particularly in times of heightened tensions. In his study of Israeli targeting killing trends, scholar Steven David found that during the Second Intifada (2000–2005), Israel embarked on such operations more than any time in its history to both deter and impede further terrorist attacks against Israelis. While in the First Intifada (1987–1993) the ratio of Palestinians to Israelis killed was roughly 25 to one, well-armed Palestinian militant groups, making use of suicide bombers, had reduced that proportion to three to one during the Second Intifada. Israel responded to these increasingly lethal attacks through increased control of Palestinian movement, military incursions into Palestinian Authority (PA)-controlled areas, and a wave of targeted killings of Palestinian militants. According to B’Tselem, an Israeli human rights organization, between September 2000 and 2006, Israeli security forces conducted at least 208 targeted killings. 

As part of its post-2000 decapitation efforts, Israel targeted both Hamas rank-and-file members and its leadership. Most of these attacks involved the use of Apache helicopters or unmanned drones firing laser-guided missiles while others employed booby-traps and undercover “Arabized” agents to conduct close-range killings. In July 2002, Israel assassinated Salah Shahada, one of Hamas’ top military leaders, using 16 bombs that also killed 15 people, including seven children, and destroyed 12 homes. Two years later, in March and April 2004, Israel killed Hamas co-founder and leader Sheikh Ahmed Yassin and his successor, Abdul Aziz al-Rantisi, in missile strikes. An irate Hamas proclaimed that, with these deaths, Israel had “opened the gates of hell”, and promised to kill “hundreds of Zionists”. 

Research into Hamas’  lethality and attack patterns following the deaths of Yassin and al-Rantisi suggests that, in some ways, its threats failed to materialize. In a 2006 Foreign Affairs piece, security analyst Daniel Byman wrote that the cumulative lethality of Hamas attacks on Israeli civilians declined—from 185 at the highest point in 2002 to 21 in 2005. 

While this drop was at least in part the result of Israel’s targeted killings, as conceded by al-Rantisi prior to his death, there is little compelling evidence that decapitation efforts reduced the overall long-term terrorist threat to Israel. Even as individual attacks became less deadly, the number of Hamas attacks steadily increased as the Intifada progressed: there were 19 attacks in 2001, 34 in 2002, 46 in 2003, 202 in 2004, and 179 in 2005 (following the Sharm el-Sheikh Summit, a de facto armistice agreement which ended the uprising in February, though violence continued). 

Public support for suicide attacks also continued to increase as the insurgency developed. Three years into the Intifada, a poll conducted by the reputable Palestinian Center for Policy and Survey Research found that 74.5 percent of Palestinians supported suicide bombings. 

Empirical studies probing the effectiveness of decapitation tactics provide some insight into Hamas’ resilience. Some scholars and proponents of targeted killing tactics argue that attacking a terrorist group’s leadership, particularly when hierarchical structures are in place, reduces its operational capability by eliminating skilled members and forcing a group to divert its time and resources to protect remaining leaders. 

Decapitations are also intended to exploit the violent and clandestine nature of terrorist groups, making leadership succession challenging and deterring others from assuming power. The argument would hypothesize that a consistent policy of targeted assassinations against leaders of terrorist groups that recruit, organize, and carry out attacks against Israeli targets would raise the cost of violence and force existing or potential militants to abandon the struggle or change tactics. 

Yet, decapitation strikes have rarely been the silver bullet against terrorist organizations, and irrespective of the normative and legalistic questions surrounding the practice, most extant literature rejects the notion that removing enemy leaders can, on its own, help achieve a state’s military and political goals. As analyst Patrick Johnston wrote in his 2012 study on counterinsurgency leadership targeting, “the scholarly opinion has been that high-value targeting is ineffective at best and counterproductive at worst.” Studies on the effectiveness of Israel’s counter-Hamas efforts have reached similar conclusions. Indeed, in a recent Foreign Affairs article, one of the field’s most acclaimed scholars, Audrey Kurth Cronin, noted that targeted killings conducted over the decades “have not affected the group’s long-term capabilities” or intentions. Its bureaucracy is partly the cause.  

The Liability of Newness and Its Effect on Terrorist Bureaucracies
Bureaucratized terrorist groups, like other bureaucratic institutions, tend to have a clear division of administrative responsibilities, roles, and functions, increasing organizational stability and efficiency. In the aftermath of a decapitation, terrorist groups are able to rely on these developed diversified functions and resource bases to withstand the sudden removal of key members or leaders. With age, bureaucracies also become larger, more complex, and durable. 

Reflecting this trend, older terrorist organizations are more resilient to decapitation tactics compared to younger ones that have not yet developed a similar organizational capacity. This “liability of newness” means that the earlier leadership decapitation occurs in a terrorist group’s life cycle, the greater the effect it will have on the group’s existence. As terrorism experts Bryan Price and Jenna Jordan found, these effects diminish in the first ten years and, once a group crosses the 20-year threshold, are unlikely to have any impact on a group’s demise. 

Now well into its fourth decade, Hamas is both a well-established and diversified bureaucratic institution. The existence of separate political, military, and social wings attests to the specific functions within the organization, each with its own roles, responsibilities, and hierarchies. Over the years, Hamas’ bureaucratic functioning and deep bench of leaders has allowed for ongoing political representation and, at the same time, has enabled the group to weather the loss of senior staff operationally. 

The overlapping power structure between Hamas’ Gazan (internal) and diasporic (external) leadership, meanwhile, has created an opportunity to garner international political and moral support for the movement while also forming an indispensable organizational backup. Following the 2004 removal of al-Rantisi, for instance, Khaled Mashal, head of the Hamas political bureau, assumed effective control of the group from his exile in Damascus. From 2017 to 2024, Ismail Haniyeh was the diplomatic and political figurehead of the group, shuttling around the Middle East from his Qatari home base, including—in recent months—to engage in indirect ceasefire negotiations with Israel. Upon his assassination in Tehran in late July, likely by Israel, Haniyeh was swiftly succeeded by Gaza-based leader Yahya Sinwar, a decision reflecting both Hamas’ symbolic defiance and internal support for a known hardliner.

Legitimizing Terrorism: Winning Hearts and Minds
Highly developed groups that enjoy widespread communal support have proven particularly difficult to displace. Indeed, one of the dilemmas that has faced Israel—and the Palestinian Authority—is that Hamas is deeply rooted in Palestinian society and, through its political–societal dimensions and services, daily life. The reasons for Hamas’ popularity, as Middle East policy analyst Khaled Hroub has argued, are not difficult to find. Hamas continues to be seen “as the voice of Palestinian dignity and the symbol of defense of Palestinian rights, a force that refuses to capitulate”.

Popular support is also essential to a terrorist group’s ability to maintain organizational strength, capacity, and legitimacy following leadership removals. Popular support enables a group to recruit, raise money, and rebuild critical resources, ensuring its continued ability to operate as a covert organization and plan future violent acts. Targeted killings can equally increase public support for the terrorists’ cause through, in counterterrorism speak, winning the “hearts and minds” of local—or international—communities. Civilian deaths resulting from the euphemistic “collateral damage” or miscalculated attacks can intensify such backlash effects, allowing terrorist groups to both enhance their ideological or political relevance and grow in popularity. 

In the case of Hamas, Israeli counterterrorism efforts, including targeted killings, have increased the movement’s legitimacy. A botched 1997 attempt to assassinate Mashal in Jordan (likely in reprisal for a Hamas suicide bombing in Jerusalem that summer), went so awry that the ensuing public and official outcry forced the Israeli government to provide an immediate antidote to the administered poison and release dozens of Hamas prisoners. Among them was Sheikh Yassin. 

According to Hroub, the 2004 assassinations of Sheikh Yassin and his successor, al-Rantisi, triggered renewed outrage and calls for vengeance, creating a paradox: even as the movement had been militarily weakened, its popularity reached new heights. Between 2000 and 2005, Palestinian support for Islamists, of which Hamas was the largest faction, rose by almost 20 percent. Aided by the perceived failure by the secular Palestinian Liberation Organization-backed Fatah to bring an end to the Israeli occupation, Hamas won 44.5 percent of the popular vote in the 2006 elections. Similar trends have unfolded after other spouts of violence and war; in a forthcoming book, analysts Beverley Milton-Edwards and Stephen Farrell explain that, “from its birth as the military wing of the Muslim Brotherhood in 1987, Hamas has operated on the working assumption: when Palestine burns, its support grows.”

Hamas Post-October 7
Eleven months after the start of Israel’s Swords of Iron operation, Hamas is, once again, enjoying a “rally round the flag” moment—even as it has endured significant military losses. From the early days of its Gaza offensive, top Israeli officials referred to Hamas members as “dead men walking” and they have sought to make good on this promise. Israel has publicly claimed to have dismantled 18 of Hamas’ 24 battalions, killed or incapacitated 14,000 Hamas fighters, and destroyed a significant portion of the group’s underground tunnel system. Since last October, Israel has reportedly also killed over 100 Hamas leaders, among them Marwan Issa, the deputy commander of Hamas’ military wing in Gaza, and Haniyeh, chairman of the Hamas Political Bureau. Some of these strikes have led to high numbers of civilian casualties. An early July strike on a designated safe zone targeting Mohammad Deif, the leader of Hamas’ military wing, for instance, reportedly killed at least 90 people and injured 300. 

Indeed, the attempted dismantlement of Hamas has come at a steep price to Palestinian civilians, a testament to the complexities of urban warfare, Hamas’ long-established strategy of embedding itself among the civilian population, and the reported loosening of Israeli constraints regarding expected civilian casualties in attacks on higher value targets—particularly in the early months of the war. According to the Hamas-run Health Ministry in Gaza, which does not distinguish between civilians and combatants, as of mid-August, more than 40,000 Gazans have been killed since October, including at least 15,000 children. As of March, sixty percent of Palestinians reported having a family member killed while 80 percent report having a family member killed or injured. Daily life for those who have survived is no longer the same; almost the entirety of Gaza’s population—some 1.9 million people—have been displaced, many repeatedly, while access to basic necessities remains wholly insufficient. 

At the same time there is little evidence that suggests that the group’s longer-term ability to threaten Israel has been significantly compromised. Hamas has, in recent months, relied both on guerilla tactics, including close-range ambushes on IDF troops, and more conventional cross-border rocket attacks on Israel. Renewed Israeli clearing operations, particularly in northern Gaza, meanwhile, suggest that Hamas fighters—along with other insurgent groups such as Palestinian Islamic Jihad—have been able to reconstitute amid security vacuums and even rebuild some governing authority.

A Defiant Hamas
“We have the Israelis right where we want them,” Hamas leader Sinwar said in a recent message to Hamas officials working to broker an agreement with Qatari and Egyptian officials. The inference here, according to the Wall Street Journal, was that Sinwar believed further Israeli hostilities and mounting Palestinian casualties—even those resulting from Hamas’ actions—played into his organization’s hands. Despite some claims to the contrary, polling conducted in the aftermath of October 7 supports his case, especially in the West Bank. Few Palestinians, it seems, blame Hamas for their suffering while the group’s commitment to violent resistance, including support for the October 7 attack, remains immensely popular. 

A poll conducted by the Palestinian Center for Policy and Survey Research found that, as of late May, 63 percent of Palestinians blamed Israel for the current suffering of Gazans; only 8 percent placed the blame with Hamas. At the same time, almost all Palestinians (97 percent) believed Israel has carried out war crimes and atrocities during the current conflict; only 9 percent believed Hamas has committed such acts, a sentiment further exemplified by the high level of satisfaction with Hamas’ performance in the current war (64 percent in Gaza and 82 percent in the West Bank, the highest recorded numbers since December 2023). Most tellingly, a majority of Palestinians appear committed to Hamas’ future in the Gaza Strip and its theory of resistance. As of June, 56 percent of Gazans believed that armed struggle is necessary to create a Palestinian state. Hamas’ long-term position, as evidenced by these numbers, is far stronger than Israel would like. The extreme devastation created by the Israeli campaign, combined with perceptions of a clear culprit, has, as security analyst Robert A. Pape recently warned, filled Gaza with angry and vengeful young men, ripe for recruitment by Hamas.  

While Israel’s post-October 7 response to Hamas is both different in kind and degree from the four other offensives that have taken place in the last 15 years, the latest war’s legacy may simply come to constitute another indefinite “grass-mowing exercise”. Indeed, while (attempted) targeted assassinations may be useful as a political tool to signal determination to punish those deemed responsible and placate an angry public, they will not bring about the end of Hamas or its ideological resonance. Hamas, in the words of analyst Adam Shatz, “feeds on despair produced by the occupation”. To starve it, then, Israel might try the opposite.