What Is Hamas?

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
  • 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.
  • Governments including the United States and European Union have designated Hamas a terrorist organization over its attacks against Israel, which have included suicide bombings and rocket attacks.
  • Israel has declared war on Hamas following its surprise assault on the country’s south in October 2023, the deadliest attack in Israeli history.


Hamas is an Islamist militant movement that has controlled the Gaza Strip for nearly two decades. It also violently rejects Israel’s existence. In October 2023, Hamas infiltrated southern Israel, killing some 1,200 people and taking dozens more hostage. In response, the Israeli military has attempted to eradicate the group, an effort that had reportedly killed more than thirty-three thousand Palestinians as of mid-April 2024. With Hamas’s regional partners—known as the “axis of resistance”—now targeting Israel, the war threatens to embroil much of the Middle East.

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Dozens of countries have designated Hamas a terrorist organization, though some apply this label only to its military wing. Iran provides it with materiel and financial support, counting it among a coalition of regional allies that includes Palestinian Islamic Jihad, Lebanon’s Hezbollah, Yemen’s Houthis, and various pro-Tehran militias in Iraq and Syria, among other groups. Along with Qatar, Turkey harbors some of Hamas’s top leaders, who have used the Turkish financial system to help fund the organization’s activities. Hamas’s rival party, Fatah, which dominates the Palestinian Authority 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?

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Palestinian Territories


Israeli-Palestinian Conflict

Terrorism and Counterterrorism

Political Movements

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.

A map of Israel and the Palestinian territories

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.

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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.”

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 (PA). 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.

More on:

Palestinian Territories


Israeli-Palestinian Conflict

Terrorism and Counterterrorism

Political Movements

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.

A graphic showing the governing structure of Hamas, with the Politburo at the top

Ismail Haniyeh currently serves as political chief, having replaced longtime leader Khaled Meshaal in 2017. Haniyeh has operated from Doha, Qatar, since 2020, reportedly because Egypt restricts his movement into and out of Gaza. Hamas leaders established a presence in Qatar 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 reportedly operate out of the group’s offices in Turkey.

Day-to-day affairs in Gaza are overseen by Yahya Sinwar, who previously headed Hamas’s military wing and served twenty-two years in an Israeli prison for masterminding the abduction and killing of two Israeli soldiers in 1988. He was among the more than one thousand Palestinian prisoners freed in 2011 in exchange for an Israeli soldier held by Hamas. As of June 2021, Gaza’s de facto prime minister is Issam al-Da’alis.

Internal elections that concluded in 2021 gave Meshaal leadership of Hamas’s diaspora office, while Salameh Katawi was elected to manage the affairs of imprisoned members. Deputy politburo chairman and Lebanon affairs director Saleh al-Arouri was voted leader of the group’s West Bank branch, a post he held until his January 2024 death by a suspected Israeli drone strike.

Marwan Issa and Mohammed Deif jointly commanded Hamas’s military wing, the Izz ad-Din al-Qassam Brigades, until Issa was reportedly killed by an Israeli air strike in March 2024, though his death is not yet confirmed. Israeli forces killed Yassin, Hamas’s founder, in 2004.

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 exacerbated the already extreme poverty in Gaza, where more than one million people needed aid before the fighting broke out. 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.

A map of Gaza with data points such as population (2.2 million) and area (360 sq km, roughly twice the size of Washington, DC)

“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 also showcased an unprecedented level of support for coordination with Hamas by Iran and its network of regional allies, an anti-West, anti-Israel coalition known as the axis of resistance. The Wall Street Journal reports that Hamas likely planned the October 7 attack with Iran’s knowledge, if not its direct authorization, though U.S. and Israeli officials have said they have no evidence of this. The axis’s subsequent attacks on Israel-linked targets, particularly by Lebanon’s Hezbollah and Yemen’s Houthis, 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. “Palestinians believe that diplomacy and negotiations are not an option available to them, that only violence and armed struggle is the means to end the siege and blockade over Gaza, and in general to end the Israeli occupation,” West Bank­–based pollster Khalil Shikaki told CNN. However, he added that “no one should see this as support for any atrocities that might have been committed by Hamas on that day.”

What’s next for Hamas?

Israel is seeking to eradicate the group and free around 130 hostages still held in Gaza, with Prime Minister Benjamin Netanyahu warning of a “long and difficult war.” After the first five months of fighting, the Israeli military had “certainly done considerable damage to Hamas, which is no longer capable of firing rockets into Israel and has seen thousands of its fighters either killed, wounded, or captured,” writes CFR Senior Fellow Steven A. Cook. Israeli officials say Hamas no longer constitutes an organized fighting force in northern Gaza, while its Gaza-based leaders, such as Sinwar, are thought to be hiding below ground in the south.

Despite these setbacks, Hamas leaders have yet to concede to Israeli demands to cease fighting and free the remaining hostages, and they reportedly envision a role for themselves in Gaza’s postwar leadership. Hamas and Palestinian Authority negotiators have held talks on cooperating in a technocratic government that administers Gaza once the fighting ends. But some experts say that the Israeli government is unlikely to accept such an outcome, having so far rejected temporary cease-fires that could have given Hamas time to regroup. “The Israelis are clearly willing to countenance international opprobrium for rejecting what they regard as a bad cease-fire deal that will allow Hamas to survive and fight another day,” Cook writes.

Recommended Resources

For Foreign Affairs, CFR Distinguished Fellow Martin Indyk discusses why Hamas attacked Israel in 2023 and why Israel was taken by surprise.

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.

Palestinian economist Raja Khalidi makes a case for establishing a Palestinian state amid the war in Gaza in this Foreign Affairs article.

The Israeli NGO Gisha maps access to the Gaza Strip [PDF] and documents restrictions on the movement of people and goods enforced by Israel and Egypt.

The European Council on Foreign Relations maps Palestinian politics.

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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