Almost a quarter century after 9/11 and the start of what became known as the war on terrorism, there is a well-worn script for the death of a major terrorist: News reports suggest a successful strike, a president or prime minister confirms the killing, there is much public joy over evil’s demise, and, finally, experts speculate about the implications of the strike. States—with enough time and resources—invariably get their men, and the house always wins. In the long run, though, the track record of decapitation is more mixed. New leaders step up, and the wars continue.

Such was the cycle for the pantheon of notorious figures—including al Qaeda in Iraq leader Abu Musab al-Zarqawi, Islamic State of Iraq emir Abu Omar al-Baghdadi, and, most prominently, al Qaeda leader and 9/11 mastermind Osama bin Laden. And so far, the fallout from the death of Hamas leader and Oct. 7 mastermind Yahya Sinwar in Gaza seems to hew closely to this narrative—including a litany of punditry about the implications of Sinwar’s demise and initial indications that war will continue for quite some time to come. And so, perhaps, it’s unsurprising that most commentators downplayed Sinwar’s death, saying some variant of “killing Sinwar changes nothing.”

Almost a quarter century after 9/11 and the start of what became known as the war on terrorism, there is a well-worn script for the death of a major terrorist: News reports suggest a successful strike, a president or prime minister confirms the killing, there is much public joy over evil’s demise, and, finally, experts speculate about the implications of the strike. States—with enough time and resources—invariably get their men, and the house always wins. In the long run, though, the track record of decapitation is more mixed. New leaders step up, and the wars continue.

Such was the cycle for the pantheon of notorious figures—including al Qaeda in Iraq leader Abu Musab al-Zarqawi, Islamic State of Iraq emir Abu Omar al-Baghdadi, and, most prominently, al Qaeda leader and 9/11 mastermind Osama bin Laden. And so far, the fallout from the death of Hamas leader and Oct. 7 mastermind Yahya Sinwar in Gaza seems to hew closely to this narrative—including a litany of punditry about the implications of Sinwar’s demise and initial indications that war will continue for quite some time to come. And so, perhaps, it’s unsurprising that most commentators downplayed Sinwar’s death, saying some variant of “killing Sinwar changes nothing.”

But that’s not entirely true. To be sure, Sinwar’s death won’t end the Israel-Hamas war, much less the Israeli-Palestinian conflict. But it will impact the war and conflict in three profound ways.

First, while Sinwar’s death cannot end the war by itself, it is a necessary condition for bringing it to a close. For better or worse, people tend to personalize their wars. World War II is embodied by Nazi leader Adolf Hitler, the Iraq war by Saddam Hussein, 9/11 by Osama bin Laden, and so on. And for many, Oct. 7 is forever linked to the scowling face of Sinwar.

Such personalization may not be entirely warranted. Hamas, after all, is a large and sophisticated organization; according to Israeli authorities, as many as 6,000 operatives had their hands in the atrocities of Oct. 7. But Sinwar, for better or worse, was the public face of the attack. And so, it’s hard to imagine Israeli President Benjamin Netanyahu—or any other Israeli premier, for that matter—ending the war with Sinwar on the loose, just as it would have been nearly impossible for a U.S. president to declare an end to the global war on terrorism with bin Laden still on the run.

At the same time, Sinwar’s death offers a chance to achieve the other necessary condition for ending the war—the release of the remaining Israeli hostages. According to U.S. National Security Advisor Jake Sullivan, Sinwar’s death removed a “massive obstacle.” Whether Sinwar’s absence will unstick the stalled negotiations remains to be seen, but the death of a leader is historically one of the catalysts for ending seemingly intractable conflicts.

Second, and more concretely, Sinwar’s death increases the chances of a more atomized, less coherent war in Gaza going forward. His death marks the culmination of an effective, brutal, and systematic destruction of Hamas’s organizational structure from the political level to the tactical roots. Israel had already killed several Hamas leaders: political chief Ismail Haniyeh, deputy political chief Saleh al-Arouri, military commander Mohammed Deif, and deputy military commander Marwan Issa, among countless other members of Hamas’s old guard. On the operational level, the Israel Defense Forces (IDF) claimed to have killed 8 brigade commanders, 30 battalion commanders, and over 100 platoon commanders. A large number of Hamas’ soldiers are dead, as well.

Killing Sinwar, then, leaves Hamas with a potential power vacuum in Gaza. The two possible successors mentioned most often—Khaled Meshaal, the group’s former political chief, and Khalil al-Hayya, a member of the group’s political bureau—are both based in Qatar. For the time being, Hamas will be run by a committee that includes Meshaal, al-Hayya, and other members also based in Qatar. That leaves Mohammed Sinwar, Yahya Sinwar’s younger brother, who reportedly took over for Deif as military commander in July. Whether Mohammed Sinwar has his brother’s charisma and can unify Hamas as an organization—especially given its losses at all levels of command and continued Israeli military pressure—remains to be seen.

And because Hamas’s structure has changed, the war in Gaza will change, as well. Israel may never wipe Hamas “off the face of the earth,” as Netanyahu pledged, but it has effectively reduced Hamas from a cohesive paramilitary organization with the size and capabilities of some smaller European militaries to a loosely affiliated, decentralized guerrilla group operating in the shadows for its own survival. That means Hamas likely won’t have the organizational backbone to conduct large-scale attacks against Israel on par with Oct. 7 any time soon. However, that also means that Hamas may lack the organizational coherence to negotiate a large-scale hostage-for-prisoner swap or agree to full cease-fire. From here on out, the war in Gaza will likely be fought as a series of local battles and potentially locally negotiated cease-fires.

Third, Sinwar’s death—at least symbolically—closes the first act of this war and sets up what comes next. Even before his death, Israel’s strategic focus had shifted northward to Hezbollah in Lebanon and increasingly eastward toward Iran. Without Hamas as its most recognizable villain, Israel’s strategic reprioritization will likely accelerate. While Israel will continue to operate in Gaza—at least so long as its reported 100 or so hostages remain unaccounted for—that’s not the story that will dominate the headlines in Israel or around the globe.

At the same time, this sets up the next phase of the broader conflict in the region. Sinwar is the latest name on the growing list of dead leaders of Iranian proxy groups, a list that now includes not only Hamas’ leadership but much of Hezbollah’s high command, as well. That’s significant because the man who built much of Iran’s proxy network, Qassem Soleimani, is dead, too. Stripped of proxies, Iran’s war with Israel, long confined to the shadows, will burst into the open.

At the same time, Sinwar’s death—or more accurately the reaction to it—highlights the increasing divide across the region and the globe. Arab states were largely muted in their response, although one Saudi TV station had its Iraq office looted after it called Sinwar and late Hezbollah leader Hassan Nasrallah terrorists. By contrast, Turkish President Recep Tayyip Erdogan paid tribute to them.

The divisions did not stop there. Many Western leaders—even critics of the Israeli government—saw Sinwar’s demise as both just and as an opportunity for peace. By contrast, the Kremlin, which welcomed Hamas leaders in the weeks after Oct. 7, expressed its “deep concerns” over Sinwar’s death, while China Daily ran a story under the headline “Sinwar killing seen detrimental to truce.” In a nutshell, Sinwar’s death became a sort of global geopolitical litmus test—with the United States and most of its allies on one side and many of its foes on the other.

This last point, above all, highlights why Sinwar’s death matters and why this incident differs from killing al-Zarqawi, al-Baghdadi, and even bin Ladin. The Israel-Hamas conflict is not just a war against a militant group or another iteration of the broader Israeli-Palestinian conflict. It has become a proxy for a host of other competing geopolitical forces shaping the Middle East and, indeed, the globe.

It just took one dead terrorist to bring that proxy war into sharper relief.