What Is Hamas?
Backgrounder

What Is Hamas?

The Palestinian militant group struggled to govern the Gaza Strip before launching a surprise attack on Israel in 2023. Now facing Israel’s military campaign to destroy it, Hamas’s future is in doubt, as is Gaza’s.
A parade for the Izz ad-Din al-Qassam Brigades, Hamas’s militant arm, is held in Gaza.
A parade for the Izz ad-Din al-Qassam Brigades, Hamas’s militant arm, is held in Gaza. Ashraf Amra/Anadolu Agency/Getty Images
Summary
  • Hamas is an Islamist militant group that spun off from the Palestinian branch of the Muslim Brotherhood in the late 1980s. It took over the Gaza Strip after defeating its rival political party, Fatah, in elections in 2006.
  • Israel declared war on Hamas following its surprise assault on the country in October 2023, the deadliest attack in Israeli history, and has killed many of the group’s senior leaders.
  • In October 2025, Hamas and Israel agreed to a ceasefire and a hostage-prisoner exchange. The swap marked an initial step in U.S. President Donald Trump’s peace plan. 

Introduction

Hamas is an Islamist militant movement that has controlled the Gaza Strip for nearly two decades. It violently rejects the existence of Israel, which it claims is occupying Palestine. In October 2023, Hamas attacked southern Israel, killing nearly 1,200 people and taking more than 200 hostages. In response, Israel declared a war aimed at eradicating the group. The conflict has killed more than sixty-four thousand people as of September 2025, according to the Hamas-run Gaza Health Ministry. A new peace plan proposed by the Trump administration in late September is currently under negotiation.

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Dozens of countries, including the United States, have designated Hamas a terrorist organization over the years, though some apply this label only to its military wing. The United States has pledged billions of dollars in new military aid since the Israel-Hamas war began and remains Israel’s top weapons supplier.

More on:

Palestinian Territories

Israel

Israeli-Palestinian Conflict

Terrorism and Counterterrorism

Political Movements

Hamas’s most important ally in the region is Iran, but it has also received significant financial and political support from Turkey. Qatar hosts the Hamas political office and also provides it with financial resources, though with the knowledge and cooperation of the Israeli government. Hamas is meanwhile one component of Iran’s so-called axis of resistance, a regional network of anti-Israel partners that includes Palestinian Islamic Jihad, Lebanon’s Hezbollah, Yemen’s Houthis, and various militias in Iraq and Syria. Given these connections, many security experts fear that the Israel-Hamas war could engulf the region in a wider conflict.

Hamas’s rival party, Fatah, which dominates the Palestinian Authority (PA) and rules in the West Bank, has formally renounced violence, though it has not always upheld that vow in times of high Israeli-Palestinian tensions. The split in Palestinian leadership and Hamas’s unwavering hostility toward Israel diminished prospects for stability in Gaza ahead of the ongoing war, which has only cast the territory into further despair.

What are the group’s origins?

Hamas, an acronym for Harakat al-Muqawama al-Islamiya (“Islamic Resistance Movement”), was founded by Sheikh Ahmed Yassin, a Palestinian cleric who became an activist in local branches of the Muslim Brotherhood after dedicating his early life to Islamic scholarship in Cairo. Beginning in the late 1960s, Yassin preached and performed charitable work in the West Bank and Gaza, both of which Israel occupied following the 1967 Six-Day War.

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Yassin established Hamas as the Brotherhood’s political arm in Gaza in December 1987, following the outbreak of the first intifada, a Palestinian uprising against Israeli occupation of the West Bank, Gaza, and East Jerusalem. At the time, Hamas’s purpose was to engage in violence against Israelis as a means of restoring Palestinian backing for the Brotherhood, which was losing political support to Palestinian Islamic Jihad (PIJ), a Gaza-based, Iran-sponsored organization that had begun pursuing terrorist operations against Israel.

Hamas published its charter in 1988, calling for the murder of Jews, the destruction of Israel, and in Israel’s place, the establishment of an Islamic society in historic Palestine. In what observers called an attempt to moderate its image, Hamas presented a new document [PDF] in 2017 that removed explicit references to killing Jews but still refused to recognize Israel. The revised charter also hinted that Hamas could accept a future Palestinian state along the borders established before the Six-Day War, which are generally recognized internationally as the borders of the West Bank and Gaza. The new document says only that the matter should depend on “national consensus.”

More on:

Palestinian Territories

Israel

Israeli-Palestinian Conflict

Terrorism and Counterterrorism

Political Movements

Hamas first employed suicide bombing in April 1993, five months before Palestine Liberation Organization (PLO) leader Yasser Arafat and Israeli Prime Minister Yitzhak Rabin signed the Oslo Accords. The historic pact established limited self-government for parts of the West Bank and Gaza under a newly created entity called the Palestinian Authority. Hamas condemned the accords, as well as the PLO’s and Israel’s recognition of each other, which Arafat and Rabin officially agreed to in letters sent days before Oslo.

In 1997, the United States designated Hamas a foreign terrorist organization. The movement went on to spearhead violent resistance during the second intifada, in the early 2000s, though PIJ and Fatah’s Tanzim militia were also responsible for violence against Israelis.

Who are its leaders?

Hamas has a host of leadership bodies that perform various political, military, and social functions. General policy is set by an overarching consultative body, often called the politburo, which operates in exile. Local committees manage grassroots issues in Gaza and the West Bank.

“The rate at which Israel has been assassinating Hamas leaders has made it increasingly difficult to determine who is in charge in the enclave,” wrote CFR Senior Fellow Steven A. Cook.

Israel has targeted top Hamas officials since the movement was founded in the late 1980s. Israeli forces killed Sheikh Ahmad Yassin, Hamas’s founder, in 2004. Since October 2023, the war in Gaza has thrown the group’s leadership into disarray, as many of its high-ranking members have been killed. Marwan Issa, deputy commander of Hamas’s military wing, was killed in an air strike in March 2024. Ismail Haniyeh, who served as political chief since 2017, was killed months later in a suspected Israeli bombing in Tehran in July. Israel also killed Hamas’s military leader, Mohammed Deif, in a strike on the southern Gaza city of Khan Younis. 

In October 2024, Israel conducted a strike that killed several Hamas militants, including Yahya Sinwar, who replaced Haniyeh as political chief. Sinwar was believed to be an architect of the October 7 attack, along with Deif and Issa, and military analysts say his killing marked a major symbolic and operational success for Israeli forces. Following Sinwar’s death, a five-person senior leadership council based in Doha, Qatar, was appointed to replace him pending elections for a new political chief, which were scheduled for March 2025 but have still not occurred. The council is composed of Khaled Meshaal, Khalil al-Hayya, Zaher Jabarin, Muhammad Ismail Darwish, and a fifth unnamed member, believed to be Mousa Abu Marzouk. Hamas leaders notably established a presence in Qatar—where Meshal, Abu Marzouk, al-Hayya, and Darwish are all believed to be—after falling out with their previous host, Syria, when Palestinian refugees participated in the 2011 uprising that preceded the Syrian Civil War. Some senior Hamas figures, including Jabarin, also reportedly operate out of the group’s offices in Turkey.

Meshaal led Hamas’s political arm in exile from 2004–2017, when he handed it off to Haniyeh, and is reportedly a top contender to replace Sinwar. Al-Hayya, who has led the group’s mediated negotiations with Israel in Qatar, is also reportedly a possible replacement. Jabarin is the head of Hamas in the West Bank. Darwish is the head of Hamas’s religious advisory body, known as the Shura Council. 

Other prominent Hamas leaders include Issam al-Da’alis, Gaza’s de facto prime minister since 2021, who was killed by Israeli forces in March, alongside several other senior Hamas officials. In May, Israel eliminated Sinwar’s brother, Mohammed Sinwar, who had become the head of Hamas’s armed wing and was one of the group’s last prominent leaders in the enclave. Currently, the highest-ranking military commander in Gaza is believed to be Izz al-Din al-Haddad or Abu Suhaib.

How is Hamas funded?

Historically, Palestinian expatriates and private donors in the Persian Gulf provided much of the movement’s funding. Today, Iran is one of Hamas’s biggest benefactors, contributing funds, weapons, and training. Though Iran and Hamas briefly fell out after backing opposing sides in Syria’s civil war, Iran provides some $100 million annually [PDF] to Hamas, PIJ, and other Palestinian groups designated as terrorist organizations by the United States, according to 2021 U.S. State Department estimates. Iran was quick to praise Hamas’s assault on Israel in late 2023 and pledge its continuing support for the Palestinian group.

Turkey has been another stalwart backer of Hamas—and a critic of Israel—following President Recep Tayyip Erdogan’s rise to power in 2002. Though Ankara insists it only supports Hamas politically, it has been accused of funding Hamas’s terrorism, including through aid diverted from the Turkish Cooperation and Coordination Agency.

Egypt and Israel closed their borders with Gaza in 2006–07, restricting the movement of goods and people into and out of the territory. For years after the blockade began, Hamas collected revenue by taxing goods moving through a sophisticated network of tunnels that circumvented the Egyptian crossing into Gaza; this brought staples such as food, medicine, and cheap gas for electricity production into the territory, as well as construction materials, cash, and arms. Egypt shut down most of the tunnels breaching its territory but began to allow some commercial goods to enter Gaza through its Salah al-Din border crossing in 2018. As of 2021, Hamas reportedly collected upward of $12 million per month from taxes on Egyptian goods imported into Gaza.

Does foreign aid for Gaza go through Hamas?

Before the current war, Israel allowed Qatar to provide Gaza with hundreds of millions of dollars in annual assistance through Hamas. But foreign aid generally reaches Gaza via the PA and UN agencies, namely the UN Relief and Works Agency for Palestine Refugees in the Near East (UNRWA), though Hamas has reportedly diverted some of this aid. As a designated terrorist entity, Hamas and its government are cut off from official assistance that the United States and European Union (EU) provide to the West Bank. Some Islamic charities in Western countries have channeled money to Hamas-backed social service groups, prompting the U.S. Treasury to freeze their assets.

The latest Israel-Hamas war has devastated the Gaza Strip, exacerbating the already extreme poverty that existed there before October 7. More than one million people needed aid before the fighting broke out; as a result of the war, about 90 percent of Gaza’s more than two million residents have been displaced, and famine conditions are setting in. The Egyptian-Israeli blockade keeps Gaza mostly cut off from the world, reliant on the little international assistance allowed past Israeli inspectors. UNRWA remains the primary aid distributor, but it suffered a massive funding cut following accusations that it employed Hamas members involved in the October 7 massacre. Its top donor, the United States, paused funding for a year in March 2024, while around a dozen other countries issued their own, open-ended pauses or announced that future UNRWA funding would depend on the results of investigations into the allegations.

How has Hamas governed Gaza?

Hamas became the de facto authority in Gaza shortly after Israel withdrew from the territory in 2005. The following year, Hamas won a majority of seats in the PA’s legislature and formed a government. It earned votes for the social services it provided and as a rejection of the incumbent Fatah, which many voters perceived as having grown corrupt at the helm of the PLO and delivering little to Palestinians through its negotiations with Israel. The outcome was unacceptable to Fatah and its Western backers, and the party ousted Hamas from power in the West Bank. In Gaza, Hamas routed Fatah’s militias in a week of fighting, resulting in a political schism between the two Palestinian territories. Palestinians have not voted for a legislature since 2006, nor a president since 2008.

“The Hamas-controlled government has no effective or independent mechanisms for ensuring transparency in its funding, procurements, or operations.”
Freedom House

As Hamas took over the remnants of PA institutions in the strip, it established a judiciary and put in place authoritarian institutions. In theory, Hamas has governed in accordance with the PA’s sharia-based Palestinian Basic Law; but it has generally been more restrictive than the law requires, including by controlling how women dress and enforcing gender segregation in public. The watchdog group Freedom House found in 2020 that the “Hamas-controlled government has no effective or independent mechanisms for ensuring transparency in its funding, procurements, or operations.” Hamas also represses the Gazan media, civilian activism on social media, the political opposition, and nongovernmental organizations (NGOs), leaving it without mechanisms for accountability.

How has Hamas challenged Israel?

For decades, Hamas’s attacks on Israel mostly involved rocket and mortar strikes, mass shootings, and suicide bombings. Iranian security officials say that Tehran has provided Hamas with some weapons, but that Hamas gained the ability to build its own missiles after training with Iran’s Islamic Revolutionary Guard Corps (IRGC) and proxies. Israeli security officials estimate that Hamas had about twenty thousand rockets and mortars in its arsenal at the start of its current war with Israel. The group has also carried out incursions into Israeli territory, killing and kidnapping soldiers and civilians.

Prior to the 2023 conflict, Hamas and Israel had their deadliest fighting in years in 2021, when Hamas fired rockets into Israel following weeks of tensions between Palestinians and Israelis in Jerusalem. Some analysts say that Hamas wanted to bolster its reputation as the defender of the Palestinian cause after the PA postponed the 2021 elections. During the eleven-day conflict, Hamas and PIJ fired more than four thousand rockets from Gaza, killing ten Israeli civilians and injuring more than three hundred others. The United States and Egypt brokered a cease-fire to the conflict.

How was Hamas’s attack on Israel in 2023 different?

Hamas’s 2023 assault on southern Israel, “Operation al-Aqsa Storm,” was extraordinary in its strategy, scale, and secrecy, analysts say. It began early on October 7, the Jewish Sabbath and an important Jewish holiday, with Hamas launching several thousand rockets into southern and central Israel, hitting cities as far north as Tel Aviv. Hamas militants also breached the heavily fortified Gaza border and infiltrated many southern Israeli towns and villages, killing nearly 1,200 people and wounding and kidnapping scores more. Fighters livestreamed videos of their actions, showing that the attack was especially brutal, with some militants appearing to perpetrate what experts say could be ruled war crimes; in March 2024, UN investigators said there were “reasonable grounds to believe” some Hamas members committed sexual violence against hostages and those killed on October 7. Military leader Mohammed Deif said Hamas undertook its assault in response to Israel’s occupation of Palestinian lands and its various “crimes” against the Palestinian people.

The October 7 attack is the deadliest in Israel’s seventy-five-year history and has inflicted a deep psychological trauma on its people, with some analysts drawing comparisons to the surprise Pearl Harbor and September 11, 2001, attacks on the United States. “It is completely unprecedented that a terrorist organization would have the capacity or the wherewithal to mount coordinated, simultaneous assaults from the air, sea, and land,” writes CFR Senior Fellow Bruce Hoffman.

The operation and the ensuing war have also drawn greater Western and international scrutiny of the military and intelligence ties between Hamas and Iran, as well as between Iran and its other “axis of resistance” allies in the region, including Lebanon’s Hezbollah and Yemen’s Houthis. While it’s unclear how much coordination there is among them, all have launched attacks on Israel or Israel-linked targets in the ongoing war, including Iran’s first-ever attack on Israeli soil in April 2024. Meanwhile, the Houthis have launched missile and drone attacks at Israel as well as frequent strikes on shipping in the Red Sea and surrounding waters, trade routes that the U.S. Navy has been tasked with defending. These extraordinary attacks have raised fears that the war in Gaza will balloon into a regional conflagration.

How do Palestinians view Hamas?

Palestinian opinions of Hamas are mixed. Before October 7, the group had been unpopular [PDF] in the Gaza Strip and West Bank, though Palestinians in both territories preferred Hamas to other political factions. Many experts say that PA President Mahmoud Abbas canceled the 2021 Palestinian national elections to prevent a likely Hamas victory.

After October 7, support for Hamas in Gaza rose four percentage points and nearly quadrupled in the West Bank, according to a December 2023 survey, though this was not enough for it to gain majority support in either territory. Gaining accurate insight into Palestinians’ views of Hamas can be difficult since open criticism of the group is often met with hostility or retribution. Still, a September 2024 poll [PDF] by the Ramallah-based Palestinian Center for Policy and Survey Research (PSR) found that support for Hamas’s offensive against Israel stood at 39 percent—18 points lower than just six months prior.

“It is important to note that support for this attack does not necessarily mean support for Hamas and does not mean support for any killings or atrocities committed against civilians. Indeed, almost 90 percent of the public believes Hamas men did not commit the atrocities depicted in videos taken on that day,” PSR noted.

What’s next for Hamas?

Israel is seeking to completely eliminate the threat that Hamas poses to Israel, with Prime Minister Benjamin Netanyahu saying that “total victory” is the objective. Israeli officials have said that Hamas no longer constitutes an organized fighting force in northern Gaza, while its Gaza-based leaders are thought to be hiding below ground in the south.

The Biden administration, with the help of the incoming Trump administration, brokered a ceasefire between Israel and Hamas that took effect in January 2025 and held for two months, before fighting resumed in March. Subsequent efforts to reach a new ceasefire agreement have proven unsuccessful. Trump announced a new peace plan in late September, with both Israel and Hamas signaling their agreement on some elements in early October, including exchanging the remaining hostages in Gaza for Palestinian prisoners. Representatives from Israel, Hamas, and the United States are set to take part in talks in Cairo to finalize the agreement, as Israeli military operations in Gaza continue in the meantime.

Hamas and PA negotiators have held talks on cooperating in a technocratic government that administers Gaza once the fighting ends, per a joint statement issued in Beijing in July 2024. But some experts say that the Israeli government is unlikely to accept such an outcome, having so far rejected temporary ceasefires that could have given Hamas time to regroup. It also remains to be seen whether Hamas would agree to the entirety of Trump’s peace plan, which calls for the group to be disarmed and stripped of governing power. 

“It is highly possible that Israel and Hamas make progress on the first points of the plan—a cessation in fighting and the exchange of hostages and prisoners—only to see the long-term components crumble and the war resume, once again,” CFR President Michael Froman wrote in early October.

Recommended Resources

Two years after Hamas’s October 7 attack, it’s clear that early choices by Israel, Biden, and Hamas set the region on a devastating trajectory that might have been avoided, CFR Senior Fellow Steven A. Cook writes for Foreign Policy.

CFR President Mike Froman and CFR Senior Fellow Steven A. Cook discuss the implications of the January Israel-Hamas ceasefire for The World This Week.

These Backgrounders by CFR’s Kali Robinson explain what to know about Palestinian governance beyond Gaza and about U.S. policy on the Israeli-Palestinian conflict.

The European Council on Foreign Relations maps Palestinian politics.

Ivana Saric, Jonathan Masters, Alice Hickson, and Zachary Laub contributed to this Backgrounder. Will Merrow and Michael Bricknell created the graphics.

For media inquiries on this topic, please reach out to [email protected].
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