Evan Gershkovich

A reporter for The Wall Street Journal, Evan Gershkovich, 32, was detained by security service agents in March 2023 during a reporting trip to Yekaterinburg, a major Russian industrial hub about 850 miles east of Moscow. Shortly after, he was charged with espionage, the first such case against a Western reporter since 1986.

In their indictment, Russian prosecutors accused Mr. Gershkovich of obtaining “secret information” about a Russian military industrial facility that produces tanks and other weapons. Mr. Gershkovich, his employer and the U.S. government have denied the charges and called them politically motivated, and prosecutors did not publicly offer any evidence of his guilt. On July 19, a Russian court in Yekaterinburg sentenced Mr. Gershkovich to 16 years in a high-security penal colony in a swift trial that only took three hearings to complete.

Alsu Kurmasheva

Alsu Kurmasheva is a Russian American editor working for Radio Free Europe/Radio Liberty, a broadcaster funded by the U.S. government. She was sentenced to six and a half years in a Russian penal colony for spreading false information about the Russian Army, a broad charge used by the Kremlin to stifle criticism of the war in Ukraine.

Ms. Kurmasheva, 47, had lived in Prague for more than two decades with her husband and two daughters. She was arrested during her trip to Kazan, her hometown about 500 miles east of Moscow. She was first fined for failing to report her American citizenship and then accused of failing to register as a “foreign agent” and put in pretrial detention. In December she was also charged with spreading false information about the Russian Army. The charges were related to a book Ms. Kurmasheva edited that featured 40 Russians who opposed the invasion of Ukraine.

Paul Whelan

Paul Whelan, 54, a former U.S. Marine who had served in Iraq, was attending a friend’s wedding in Moscow at the swanky Metropol Hotel when he was arrested on Dec. 28, 2018.

Mr. Whelan had made several previous trips to Russia, so he readily accepted a flash drive that a Russian friend said contained pictures of his travels. Russian agents then swooped down, claiming the drive held classified Russian military information.

Mr. Whelan is a citizen of the United States, Canada, Britain and Ireland. He was sentenced to 16 years in a high-security penal colony, where he was forced to sew industrial garments and suffered at least one assault by another inmate. He spoke out repeatedly about being left behind while other Americans were exchanged.

Ilya Yashin

A longtime fixture of Russian opposition politics, Ilya Yashin was sentenced in December 2022 to eight and a half years in prison after a court found him guilty on charges of “spreading false information” about atrocities committed by Russian troops in the Ukrainian city of Bucha, near Kyiv.

Previously, he served as the chairman of a municipal council in one of Moscow’s districts and took part in many anti-Kremlin protests. After the death of Aleksei Navalny, Mr. Yashin, 41, is considered to be one of the most popular Russian opposition leaders.

Before his arrest, he spoke about the war in Ukraine on his YouTube channel, often voicing criticism of President Vladimir V. Putin and his “special military operation.” While many Putin critics have fled Russia, especially immediately after its invasion of Ukraine, Mr. Yashin vowed to remain, even if it meant serving prison time.

Oleg Orlov

A veteran activist and human rights defender, Oleg Orlov, 71, served as a leading member of the Memorial, one of the oldest human rights organizations in Russia. Memorial started in the late 1980s as a grass-roots effort dedicated to researching mass purges under Stalin.

Over years, the Russian state grew increasingly wary of Memorial and its members. In 2021, a Russian court ordered it to be dissolved for failure to fulfill its duties as a “foreign agent” after the government designated the group as such. The next year, Memorial was awarded the Nobel Peace Prize.

In February, a Moscow court sentenced Mr. Orlov to two and a half years in prison for repeatedly discrediting Russia’s military by voicing his opposition to the war in Ukraine.

Vladimir Kara-Murza

A veteran Russian activist, Vladimir Kara-Murza, was sentenced to 25 years in prison for treason, the longest sentence given to an opposition politician in modern Russia. Mr. Kara-Murza, 42, drew the Kremlin’s ire when he lobbied in Washington for the use of sanctions to punish Russian government officials engaged in human rights abuses. In 2024, Mr. Kara-Murza, a Russian-British national and permanent resident of the United States, was awarded the Pulitzer Prize in commentary for columns he had written in his prison cell and published in The Washington Post.

Mr. Kara-Murza twice survived what he characterized as government attempts to poison him — both times he was hospitalized in critical condition with organ failure.

Released by Germany

Vadim Krasikov

Vadim N. Krasikov, 58, is a Russian citizen who was sentenced to life in prison in Germany in 2021 for the brazen assassination of a Chechen separatist fighter in broad daylight in a park in central Berlin in 2019. German prosecutors indicated in their case that Mr. Krasikov worked for the Russian Federal Security Service, the most powerful security agency in Russia. The German judge suggested that the killing was ordered by Mr. Putin; the Kremlin denied involvement.

In a televised interview in February, Mr. Putin spoke glowingly of Mr. Krasikov, calling him “a person, due to patriotic sentiments, eliminated a bandit in one of the European capitals.”

The organization has operated letter-writing campaigns, launched social media blitzes and staged a 24-hour read-a-thon of Mr. Gershkovich’s reporting. Colleagues across the world took part in runs on the first anniversary of his arrest, while employees in New York plunged into the cold waters at Brighton Beach in Brooklyn for a swim event.

“After an initial flurry of attention in the weeks following Evan’s arrest, keeping the spotlight on his ordeal became a huge challenge for the newsroom amid jam-packed news cycles,” Emma Tucker, the editor in chief of The Journal, told The New York Times in an email earlier this year.

“We used every grim milestone as a moment to organize publicity and get Evan back into the headlines: 100 days, his birthday in October, 250 days, every one of his court appearances,” she wrote.

The Journal has continuously and strenuously denied the espionage charges against Mr. Gershkovich, saying he was an accredited journalist doing his job.

His arrest happened just five weeks after Ms. Tucker began her tenure as The Journal’s top editor. The Journal set up a dedicated section on its website featuring news updates on Mr. Gershkovich. It also has a counter logging the number of days since he had been arrested and it included resources for writing messages of support to Mr. Gershkovich and his family.

In October, The Journal moved its Washington bureau chief, Paul Beckett, into a new role to work full time on securing Mr. Gershkovich’s release.

Mr. Gershkovich’s family members, who live in the United States, are in regular contact with The Journal, which has helped to coordinate their interviews with the media.

On March 29, to mark his year of detainment, The Journal wrapped its newspaper in a special section with a blank front page bearing the headline “His Story Should Be Here.”

Video of the funeral showed Iran’s supreme leader, Ayatollah Ali Khamenei, and its new president, Masoud Pezeshkian, wiping away tears during prayers for Mr. Haniyeh. Although Iran supports Hamas in the nearly 10-month war against Israel, Mr. Haniyeh’s funeral displayed an unusual outpouring of emotion by leaders of the Shiite government for a Sunni militant.

In a social media post after the funeral, Iran’s government said Mr. Pezeshkian had called an unnamed Hamas official in the organization’s political office to convey that “Iran has not failed to support the oppressed Palestinians and continues to support the resistance with a firmer determination.”

Additionally, the Iranian foreign minister, Ali Bagheri, called Egypt’s top diplomat to press for an emergency meeting of the Organization of Islamic Cooperation, demanding “all regional Muslim states to take a measure in order to counter the terrorist aggression,” according to a government statement.

Iran and Hamas blame Israel for killing Mr. Haniyeh, who had been in Tehran to attend Mr. Pezeshkian’s inauguration. American officials have also assessed that Israel was responsible for the attack, although Israel has not publicly acknowledged that.

In contrast, Israel was quick to describe a strike it launched in Lebanon on Tuesday night, killing a senior Hezbollah official, hours before Mr. Haniyeh was assassinated with an explosive device nearly 1,000 miles away. The funeral for the Hezbollah official, Fuad Shukr, was also held on Thursday.

The strikes, and pledges of retaliation by Iran and its allies, have raised concerns among Western officials about a wider regional war.

During prayers for Mr. Haniyeh in Tehran, Mr. Khamenei appeared to repeatedly look up and scan the sky, prompting social media speculation that he was worried about being targeted during the funeral.

The tension in the region intensified on Wednesday morning, when Hamas and Iran accused Israel of assassinating Ismail Haniyeh, one of the most senior Hamas leaders. Israel has not addressed the killing.

“There’s no doubt that an attack by Hezbollah, which knows and is capable of operating abroad, should increase the level of security provided to the delegation,” Shmulik Philosof, a former head of a Shin Bet unit that was responsible for securing Israeli delegations, said of the Israeli team now competing in the summer Olympics.

Concerns for the Israeli team — which has been shrouded in protection at every Games since 11 of its athletes and coaches were killed at the Munich Olympics in 1972 — have substantially increased since the Oct. 7 terrorist attacks, the subsequent war in Gaza, global protests and continuing threats.

Before traveling to Paris, Israeli athletes reported receiving anonymous emails that threatened, “we intend to repeat the events of Munich 1972.”

Mark Adams, a spokesman for the International Olympic Committee, would not comment on whether security had been augmented Wednesday for the Israeli team. “Rest assured there is very good, very strong security,” he said.

The French authorities have dedicated a special team to protect the Israeli delegation, according to Mr. Philosof, as host countries have done in previous Olympics. But, he added, “our policy is not to rely solely on local security anywhere, ever.”

Israel is one of the few nations that rely on its own security operation to supplement the security provided by the Olympic host country. Shin Bet, Israel’s domestic security agency, spent two years preparing the plan for the Paris Olympics, a process that included numerous meetings between agency officials and their French counterparts, according to two former Shin Bet senior officers. In early June, Israel’s culture and sports minister, Miki Zohar, said the delegation’s security budget had increased by 50 percent.

Israeli athletes had already been preparing for an abnormal Olympic experience. They expected their time at the Games to be marked as much by protests, heavy security, intense scrutiny and questions around politics and the war raging in Gaza as their own competitions.

“It’s a bummer, but it is what it is,” Maor Tiyouri, an Israeli marathoner, said before she arrived in Paris.

Ms. Tiyouri, who also ran the marathon at the Tokyo Olympics three years ago, has competed internationally since she was 16. Now 33, she doesn’t wear any national gear when she travels, she said, and has taped over the Israeli flag on her national team backpack.

“It’s always been this way,” Ms. Tiyouri, said, adding, “It’s hard but that’s just the reality of things, and if that means I’m more safe, then that’s what I’m going to do.”

It’s not so different for Anat Lelior, an Israeli surfer, who has reached the round of 16 in the women’s event. Representing Israel is “nowadays a lot different,” she said from Teahupo’o, Tahiti, where the surfing competition is being held. “I don’t go around saying I’m Israeli as much as I have, just for my safety.”

Israeli athletes have been instructed to not engage in protests or discussions, or to share their own opinions about the war, regardless of what they may be. Being asked to censor themselves is exhausting yet expected, many say. The athletes said they felt that to many, they were a flag — not a person or athlete with their own beliefs or political views but a repository for anger or frustration.

There have been some strained interactions among athletes. Adam Maraana, an 100-meter backstroke swimmer and the first Israeli-Arab to represent Israel since 1976, tried to swap pins with Algerian athletes but was turned away, he said. (Pin trading is a tradition at the Olympic Games. Countries, sports and brands make special Olympic pins, and athletes flash their finds along their identification lanyards.)

“I do understand it’s their choice, but it’s a little bit disappointing,” Maraana said.

Still, athletes are clinging to the joy of participating in the Olympics.

Itamar Einhorn, a soft-spoken Israeli cyclist competing in his first Olympics, has worked to balance the emotions and complexities that come with representing Israel with the fulfillment of a childhood dream.

News back home affects him a lot of the time. But, he said, with a sigh, “This is a very special experience.”

He has been revered within some Palestinian circles for overseeing the development of Hamas’s military abilities and has been a symbol of the group’s resilience, finding ways to survive despite being a top target of one of the most powerful militaries in the Middle East.

On Oct. 7, as Hamas launched an attack on Israeli towns and military installations, Mr. Deif released a recorded speech declaring that the group had launched its operation so “the enemy will understand that the time of their rampaging without accountability has ended.”

“Righteous fighters, this is your day to bury this criminal enemy,” he said in the speech, which was broadcast on Hamas’s Al-Aqsa TV. “Its time has finished. Kill them wherever you find them,” he added. “Remove this filth from your land and your sacred places. Fight and the angels fight with you.”

Hamas is backed by Iran, and Mr. Deif has supported the relationship.

He has not been seen publicly in years, and few photographs of him are in the public domain. In January, the Israeli Army published an image of a man it said was Mr. Deif; the picture showed him resting under a tree with a wad of cash in hand.

He is believed to have been disabled, possibly missing an eye and limbs. Israel bombed his home in 2014, killing his wife and infant son.

In May, Karim Khan, the International Criminal Court’s prosecutor, requested an arrest warrant for Mr. Deif, accusing him and two other Hamas leaders of war crimes and crimes against humanity. Hamas rejected the prosecutor’s claims.

Mr. Deif was born in 1965 to a poor Palestinian family and grew up in the Khan Younis refugee camp near Yahya Sinwar, the leader of Hamas in Gaza, and Mohammed Dahlan, an exiled leader of Fatah, another Palestinian faction that rivals Hamas.

Ibrahim Madhoun, an analyst close to Hamas, said of Mr. Deif in an interview: “His fingerprints are on the transformation of the Qassam Brigades from a limited number of armed cells to a formal army that has tens of thousands of fighters.”

Mr. Deif commanded the so-called Shadow Brigade, which guards Israeli captives held by Hamas, and invested significantly in manufacturing weapons and bringing new technologies to the Qassam Brigades such as reconnaissance drones, Mr. Madhoun said.

“Following an intelligence assessment, it can be confirmed that Muhammad Deif was eliminated in the strike,” the Israeli military statement said, without offering any more specific evidence that he was dead.

At least 90 people on the ground in the vicinity of the strike were killed that day, according to the Gazan health ministry. Its tally does not distinguish between civilians and combatants, but health officials said some were women and children.

Mr. Deif, who survived several previous Israeli assassination attempts, has been the No. 2 Hamas leader inside Gaza. He is the highest-ranking Hamas figure inside Gaza that Israel says it has killed since Oct. 7.

Israel’s government made eliminating Hamas’s leadership a stated goal of the war, and Mr. Deif’s death would be counted as a victory in that effort. How Hamas’s operations could be affected remains to be seen, though: Israel has killed many senior commanders in the past, only to see the group swiftly replace them.

The announcement came a day after the assassination of Ismail Haniyeh, the Qatar-based leader of Hamas’s political bureau. He was killed in an explosion in the Iranian capital, Tehran. Both Hamas and Iran blamed Israel, which has not confirmed or denied its involvement.

Mr. Deif has been de facto second in command to the group’s leader inside Gaza, Yahya Sinwar.

Born in 1965 to a poor Palestinian family, Mr. Deif grew up in the Khan Younis refugee camp and joined Hamas as a young man, around the time the group was founded in the late 1980s.

He quickly rose through the organization’s ranks, developed a reputation as a master bomb maker and orchestrated a number of attacks on Israel, including a series of deadly bus bombings that undermined the Israeli-Palestinian peace process in the mid-1990s.

Analysts credit him with transforming Hamas’s military wing, the Qassam Brigades, into a powerful and well-organized fighting force with tens of thousands in its ranks.

Mr. Deif’s success at escaping previous Israeli efforts to kill him — he was believed to have lost an eye and been seriously wounded — only enhanced his status in the eyes of some Palestinian admirers.

He survived more than eight attempts on his life, according to Israeli intelligence. In 2014, an Israeli airstrike killed one of his wives and at least one of his children, an infant son. In a brief 2021 conflict in Gaza, Israel’s military said it had tried to kill him several times.

When the Oct. 7 attack on Israel was underway, Mr. Deif released a recorded speech saying that Hamas had launched the assault so that “the enemy will understand that the time of their rampaging without accountability has ended.”

Since October, Israel has again had Mr. Deif in its cross hairs, killing his deputy, Marwan Issa, in March.

In May, Karim Khan, the International Criminal Court’s chief prosecutor, requested a warrant for Mr. Deif’s arrest, accusing him and two other Hamas leaders of war crimes and crimes against humanity. The prosecutor also sought arrest warrants for Israel’s prime minister, Benjamin Netanyahu, and its defense minister, Yoav Gallant.

Hamas criticized Mr. Khan for seeking to prosecute its leaders alongside Israeli officials, which it deemed “equating between the executioner and the victim.”

Mr. Deif spent decades underground in the tunnel network that typically shields Hamas leaders, according to Israeli intelligence officials, and had not been seen publicly in years. But officials recently said the Israeli military believed that he had developed health problems that forced him to spend more time above ground.

The strike that the Israeli military said killed him was authorized after prolonged surveillance of a house in southern Gaza where another top Hamas lieutenant, Rafa Salameh, was believed to be staying with his family, according to Israeli officials.

After learning that Mr. Deif appeared to be at the location, Israeli fighter jets struck with at least five precision-guided bombs, the officials said. Israel has said Mr. Salameh was also killed, a claim Hamas has not directly addressed.

That evening, Mr. Netanyahu said that an airstrike had targeted Mr. Deif but that there was not yet “absolute certainty” as to whether he had been killed.

“His hands are steeped in the blood of many Israelis,” Mr. Netanyahu said. “At the beginning of the campaign, I laid down a rule: The Hamas murderers are dead men, from the first to the last.”

Cassandra Vinograd and Rawan Sheikh Ahmad contributed reporting.

The official who shared the image spoke on the condition of anonymity because he was not authorized to speak publicly. The photo, which is circulating on Telegram channels affiliated with Iran’s Revolutionary Guards, shows a six-story structure in the upscale, leafy neighborhood of Zafaranieh in northern Tehran. The building is adjacent to the Saadabad Palace, which is used for government ceremonies. Its location is consistent with early reports of an explosion in northern Tehran, and The Times matched the building visible in the photo with satellite imagery of the site, confirming it is a building at the northern edge of Tehran.

One corner of the building appears to have sustained damage and is covered with a green cloth. Rubble can be seen on the roof of the first floor.

Just six days ago, another image of the same building, taken by the satellite company Maxar Technologies on July 25, shows no visible damage and no green tarp. That suggested that the image showing damage was taken more recently. It was not clear exactly when the tarp was placed on the building.

“The assassination of Ismail and Rami, while they were documenting the crimes of Israeli forces, underscores the urgent need for immediate legal action against the occupation forces to ensure that there is no impunity,” Al Jazeera Media Network said in a statement.

Mohammed Moawad, Al Jazeera’s managing editor, praised Mr. al-Ghoul’s courage in a post on social media.

“Ismail was renowned for his professionalism and dedication, bringing the world’s attention to the suffering and atrocities committed in Gaza,” he said.

The Committee to Protect Journalists has said the war in Gaza has led to the deadliest period for correspondents since it began gathering data in 1992, with at least 111 journalists and media workers among the more than 39,000 people killed in Gaza.

Mr. Moawad posted a message that he said had been written by Mr. al-Ghoul, in which the journalist reflected on being haunted by the incessant civilian suffering and death he’d seen while reporting on the conflict in Gaza.

“Let me tell you, my friend, that I no longer know the taste of sleep,” Mr. al-Ghoul wrote. “The bodies of children and the screams of the injured and their blood-soaked images never leave my sight. The cries of mothers and the wailing of men who are missing their loved ones never fade from my hearing.”

He added: “I am tired, my friend.”

An Al Jazeera video from outside a hospital showed two corpses on stretchers wearing vests meant to protect journalists, marked with the word “press.” The journalists were on their way to a hospital after being asked to leave the area by Israeli forces, according to Al Jazeera.

Jodie Ginsberg, the chief executive of the Committee to Protect Journalists, said in a statement on social media that the organization was “dismayed” by the journalists’ deaths.

“Journalists are civilians and should never be targeted,” she said. “Israel must explain why two more Al Jazeera journalists have been killed in what appears to be a direct strike.”

The Israeli military did not immediately respond to a request for comment on Wednesday.

Israel has a fraught relationship with Al Jazeera. In May, the Israeli government shut down the organization’s local operations in a step that critics denounced as anti-democratic and part of a broader crackdown on dissent over the war against Hamas.

Prime Minister Benjamin Netanyahu has accused Al Jazeera, a major source of news in the Arab world that has often highlighted civilian suffering in Gaza, of harming Israel’s security and inciting violence against its soldiers, though Israeli officials offered no examples. The initial order to shut down, set for 45 days, has since been extended.

The New York Times and other major international outlets have evacuated Palestinian journalists who had been working for them in Gaza. Israel and Egypt have restricted entry by international journalists into Gaza — with the exception of coordinated visits to specific sites with the Israeli military — so the stories that emerge from the war have often been left to local Palestinian reporters to document alone, working in extremely dangerous conditions.

“It is clear that journalists need to be protected,” Stéphane Dujarric, a United Nations spokesman, told reporters in a briefing on Wednesday. “These and other similar incidents must be fully and transparently investigated, and there must be accountability.”

Anushka Patil contributed reporting.

Iran and Hamas have accused Israel of the assassination; Israel, which is at war with Hamas in the Gaza Strip, has neither acknowledged nor denied killing Mr. Haniyeh, who was in Tehran for the inauguration of Iran’s new president. Israel has a long history of killing enemies abroad, including Iranian nuclear scientists and military commanders.

Through almost 10 months of war in Gaza, Iran has tried to strike a balance, putting pressure on Israel with sharply increased attacks by its allies and proxy forces in the region, while avoiding an all-out war between the two nations.

In April, Iran made its biggest and most overt attack on Israel in decades of hostility, launching hundreds of missiles and drones in retaliation for an Israeli strike on its embassy compound that killed several Iranian military commanders in Damascus, Syria. But even that show of force was telegraphed well in advance, nearly all the weapons were shot down by Israel and its allies, and little damage was done.

Now it is unclear how forcefully Iran will respond, and whether it will once again calibrate its attack to steer clear of escalation. Iranian military commanders are considering another combination attack of drones and missiles on military targets in the vicinity of Tel Aviv and Haifa, but would make a point of avoiding strikes on civilian targets, the Iranian officials said. One option under consideration is a coordinated attack from Iran and other fronts where it has allied forces, including Yemen, Syria and Iraq, for maximum effect, they said.

Mr. Khamenei, who has the last word on all state matters and is also the commander in chief of the armed forces, instructed military commanders from the Revolutionary Guards and the army to prepare plans for both an attack and a defense in the event that the war expands and Israel or the United States strike Iran, the officials said.

In his public statement about Mr. Haniyeh’s death, Mr. Khamenei signaled that Iran would retaliate directly, saying, “we see avenging his blood our duty,” because it happened on the territory of the Islamic Republic. He said Israel had set the stage for receiving “a severe punishment.”

Statements from other Iranian officials, including the new president, Masoud Pezeshkian, the foreign ministry, the Guards and Iran’s mission to the U.N., also said openly that Iran would retaliate against Israel and that it had a right to defend itself against a transgression on its sovereignty.

Iran and the regional forces it backs — Hamas, Hezbollah in Lebanon, the Houthis in Yemen and multiple militias in Iraq — form what they call the “axis of resistance.” Leaders of those groups were in Tehran for the inauguration of Mr. Pezeshkian on Tuesday. Mr. Haniyeh was assassinated at about 2 a.m. local time, after attending the ceremony and meeting with Mr. Khamenei.

The killing shocked Iranian officials, who described it as crossing red lines.

It was a humiliating security breach for a country eager to project strength but long frustrated by its inability to prevent Israel from carrying out covert operations on its soil. The embarrassment was compounded by Mr. Haniyeh’s prominence, the presence of other allies, and that he was attacked at a highly secure Revolutionary Guards guesthouse on a day of heightened security in the capital.

Many Iranian supporters of the government and officials expressed outrage at the failure to thwart the assassination, saying only a handful of senior security officials would have known where Mr. Haniyeh was staying. Some took to social media to say that Iran’s first priority should be to clean house and ensure the safety of its senior officials.

“Before revenge first ensure the safety of the supreme leader,” said Alireza Katebi Jahromi, a journalist and supporter of Iran’s government, in a post on X.

Iranian officials don’t view Mr. Haniyeh’s assassination as just Israel’s opportunistic killing of one of its foes, but also as an affront to their security apparatus that suggests anyone in Iran, at any level, could be targeted and killed.

Analysts said that Iran sees retaliation as necessary for both avenging the killing of Mr. Haniyeh but also deterrence against Israel killing other powerful enemies, like Hassan Nasrallah, the leader of Hezbollah, or Gen. Ismail Qaani, the commander of the Quds Forces who oversees the militant groups outside Iran.

“Iran likely believes it has no choice other than retaliating to deter further Israeli attacks, defend its sovereignty, and preserve its credibility in the eyes of its regional partners,” said Ali Vaez, the Iran director of the International Crisis Group.

The group’s leadership structure is often opaque, but here is a look at what we know about some of Hamas’s most prominent leaders who are either believed to be alive or whose fate is unclear.

Yahya Sinwar, the head of Hamas in Gaza

Mr. Sinwar helped establish Hamas in the late 1980s around the time of a Palestinian uprising against Israeli rule. He was arrested by the Israeli authorities several times, spending over 20 years in Israeli prison until he was released in a prisoner exchange in 2011.

After rising through Hamas’s ranks, he was elected its leader in Gaza in 2017. Israeli officials said that he was one of the leaders who had masterminded the Oct. 7 attack, alongside Mohammed Deif, the commander of Hamas’s military wing in Gaza, and Marwan Issa, the deputy commander, who was killed in an Israeli strike in March. Mr. Sinwar is believed to be hiding in the group’s tunnel network beneath Gaza.

A number of Hamas’s leaders in Gaza, including Mr. Sinwar, are seen as more radical than Mr. Haniyeh, the leader who was killed in Iran. The death of Mr. Haniyeh, who was considered a relatively pragmatic counterpoint, “will make a cease-fire much more difficult to achieve,” said Hugh Lovatt, a senior policy fellow at the European Council on Foreign Relations.

Khaled Meshal, a former political head of Hamas

Born near the West Bank city of Ramallah, Mr. Meshal became the leader of Hamas’s political office in 1996, directing the group from exile. Two years later, Israeli agents injected him with a slow-acting poison in Jordan, sending him into a coma before he was saved by an antidote provided by Israel as part of a diplomatic deal with Jordan.

Mr. Meshal spent his career moving from one Arab nation to another, living in Kuwait, Jordan, Qatar and Syria. When he stepped down as head of the political office, he was succeeded in 2017 by Mr. Haniyeh. Mr. Meshal, who is still influential in the organization, remains a top official in the group.

Khalil al-Hayya, the deputy leader of Hamas in Gaza

Mr. al-Hayya, who lives in exile, has been a Hamas official for decades and is currently Mr. Sinwar’s deputy. He survived an Israeli assassination attempt in 2007, when an airstrike on his home in Gaza killed members of his family while he was not there.

He was thought to be a contender to succeed Mr. Haniyeh in future internal Hamas elections, Mr. Lovatt said.

Mousa Abu Marzouk, a member of Hamas’s top political bureau

One of Hamas’s founders, Mr. Abu Marzouk started his political career in the United Arab Emirates, where he helped found a branch of the Palestinian Muslim Brotherhood, from which Hamas was formed, according to the European Council on Foreign Relations.

He later went to the United States, where he helped found Islamic institutions, including those focused on the Palestinian cause. In 1996, he faced Israeli charges of financing and helping organize terrorist attacks, when he headed Hamas’s political bureau. After 22 months spent in a Manhattan jail on suspicion of terrorism, he agreed to relinquish his permanent residence status in the United States and said he would not contest the terrorism accusations that led to his detention. The United States then deported him to Jordan.

He is now a senior member of the political bureau and splits his time between Gaza, Egypt and Qatar. He is another member of the cast of likely successors to Mr. Haniyeh, Mr. Lovatt said.

Muhammad Deif, the commander of Hamas’s military

Mr. Deif, another of the suspected planners of the Oct. 7 attacks, joined Hamas as a young man soon after its founding. In 2002, he became the leader of Hamas’s military wing, the Qassam Brigades, succeeding its founder, who was killed in an Israeli strike. Mr. Deif has since orchestrated multiple attacks on Israel, including a series of suicide bombings in 1996.

Last month, Israeli forces bombarded a densely packed coastal area of Gaza with heavy munitions in an attempt to kill Mr. Deif. Scores of Gazans were killed in the attack. Israel’s military said on Thursday that it had killed Mr. Deif in the strike. Hamas has neither confirmed nor denied his death.

He had been at the top of Israel’s list of most-wanted terrorists for decades, earlier evading more than eight attempts on his life, according to Israeli intelligence. In 2014, an Israeli airstrike killed one of his wives and their infant son. Israeli officials believe that Mr. Deif, who for years has not been seen publicly, has spent much of the past decades in Hamas’s underground tunnels.

Aaron Boxerman contributed reporting.

Israel’s Tuesday night strike on Fuad Shukr, a senior Hezbollah commander in Beirut, was a response to an attack on an Israeli-controlled town on Saturday that killed 12 children and teenagers. The strike on Beirut was the first time during this war that Israel has targeted such an influential Hezbollah leader in Lebanon’s capital. Hours later, the killing in Iran of Hamas’s political leader, Ismail Haniyeh, was considered the most brazen breach of Iran’s defenses in years.

Taken together, the seniority of the targets, the sensitive location of the strikes and their near simultaneity were viewed as a particularly provocative escalation that has left the region fearing an even bigger response from Iran and its regional proxies, including Hezbollah, the Houthis in Yemen and militias in Iraq. The scale of that reaction could determine whether the low-level regional battle between Israel and the Iranian alliance tips into a full-scale, all-out conflict.

Iranian military commanders are considering a large combination attack of drones and ballistic missiles on military targets in Israel but would avoid striking civilian targets, three Iranian officials have said.

Still, while Iran and Hezbollah are likely to respond, they may yet choose methods that give Israel room to avoid further retaliation, at least for now, some analysts said. For months, Hezbollah has appeared wary of a war that would likely devastate Lebanon, while Iran — whose leadership has already said it will respond forcefully — may want to avoid actions that draw the United States into the conflict more directly. Both parties may also decide to view each assassination as a distinct event, rather than as a combined attack that requires a massive, joint response, analysts said.

Hezbollah will face pressure to respond because the strike on Beirut hit one of its own commanders, rather than one of its allies, according to Michael Stephens, a non-resident expert on the Middle East at the Foreign Policy Research Institute, a Philadelphia-based research organization. But it is by no means clear that Mr. Haniyeh’s death in Iran will change Hezbollah’s calculations in Lebanon, Mr. Stephens said.

“We need to be very clear and very careful about how we conflate the two issues,” Mr. Stephens said. “Over the past nine months, Hezbollah has repeatedly shown that what happens to Hamas is not related to Hezbollah’s strategic imperatives. That doesn’t mean there won’t be conflict. I just think the route to getting there is more complex than it seems.”

For Iran, the attack on its soil was deeply embarrassing in part because it occurred the same day as the country’s newly elected president was being inaugurated, exposing Iran’s security vulnerabilities. Still, because the attack targeted a foreign guest rather than senior Iranian officials, Iran has some room to calibrate its response, according to Andreas Krieg, an expert on the Middle East at King’s College, London.

“I don’t think necessarily that the Iranians’ strategic calculus has changed,” Mr. Krieg said.

“Iran will have to respond in some way,” he said. “But it’s not a turning point.”

Some analysts said the killing of Mr. Haniyeh, Hamas’s top negotiator, made a cease-fire deal in Gaza less likely in the immediate future. Israelis hoped that the killing of such an influential leader would eventually help break Hamas’s resolve, making the group more willing to compromise in the long term. But others said that the organization was unlikely to be seriously affected by Mr. Haniyeh’s death.

Despite his title as Hamas’s political leader, Mr. Haniyeh is replaceable, said Joost Hiltermann, the Middle East and North Africa program director for the International Crisis Group.

“Hamas will survive,” he said. “They have plenty of other leaders.”

While escalation is more likely now that at any time since October, past experiences show that de-escalation is still possible. In January, Israeli strikes killed a senior Hamas leader in Hezbollah’s stronghold in Beirut, leading to fears that Hezbollah would mount a particularly fierce response on Hamas’s behalf. Days later, Hezbollah instead chose what was construed as a largely symbolic response, firing a barrage of rockets at an Israeli army base that caused little damage. And after Israel killed several Iranian commanders in Syria in April, Iran responded with one of the biggest barrages of cruise and ballistic missiles in military history. After a symbolic Israeli counterstrike, the two sides then chose to step back from the brink.

But even if an escalation is averted, it is unclear what the two strikes will achieve for Israel strategically.

To some of Israel’s critics, they were an attempt to set off a regional war. To dispel that idea, Israel’s foreign minister, Israel Katz, said on Wednesday that a bigger war could still be avoided if both sides adhered to a United Nations resolution that was issued after the last major war between Israel and Hezbollah in 2006, but never enforced.

Resolution 1701 called for Hezbollah’s withdrawal from the Israeli border, among other stipulations. “Israel is not interested in an all-out war, but the only way to prevent it is the immediate implementation of Resolution 1701,” Mr. Katz said in a statement.

In Israel, the two strikes were hailed as an impressive show of strength and the product of an intricate intelligence-gathering operation. But Israelis also questioned their strategic benefit, beyond settling scores with Hamas for its Oct. 7 attack on Israel and Hezbollah for the strike on Saturday that killed 12 children and teenagers. (Hezbollah denied it was behind that attack.)

Once the dust settles, more than 100 Israeli hostages will still remain captive in Gaza, Hamas will remain undefeated, and Hezbollah will continue pose a strategic threat along Israel’s northern border. And Iran will still exert influence over several proxy powers that threaten U.S. and Israeli interests in the region.

“Nothing is resolved,” said Itamar Rabinovich, Israel’s former ambassador to Washington. For Israelis, the strikes “lift the spirit here without solving any of the underlying issues,” Mr. Rabinovich said. “We are where we were.”

Some said the double assassination could provide a way out of the war altogether by allowing Prime Minister Benjamin Netanyahu of Israel to claim a symbolic victory, giving him space to back down in Gaza and perhaps agree to a cease-fire.

But Mr. Netanyahu may still avoid doing so if he believes a truce would result in the collapse of his government; his ruling coalition relies on far-right lawmakers who have threatened to quit the alliance if the war ends without Hamas’s defeat.

Vivian Yee contributed reporting.