As the world approaches one year following the outbreak of war between Israel and Hamas, another Middle East conflict is rapidly brewing. The Israel Defense Forces’ focus is now split between Gaza in the south and a confrontation with Hezbollah in the north, as Israeli airstrikes could give way to an invasion of southern Lebanon. Meanwhile, Israeli-Iranian tensions have erupted into hostilities as Iran launched hundreds of ballistic missiles at Israel in retaliation for Israeli assassinations against key leaders of Iranian proxies.

But as the world holds its breath for what comes next in Lebanon and across the greater Middle East, the one-year anniversary of the Hamas attacks that triggered so much regional turmoil offers an opportunity to take a step back and examine the lessons learned from the war in Gaza, which continues to this day. For the United States this is crucial because this war was one of the least expected but is perhaps most consequential to America’s strategic posture in the Middle East and the world at large. Three critical lessons from Gaza stand out: first, strategic surprise in the Middle East remains a high probability despite advanced military technology; second, tunnel warfare has proven to be a major advantage for defenders like Hamas; and third, Hamas’s sustainment operations have allowed it to rebuild its forces and continue fighting without making significant political concessions.

Strategic Surprise: A Defining Element of Modern Middle East Conflict

Strategic surprise remains a significant possibility, particularly in the Middle East and given the unconventional posture of Iran’s axis of resistance. For example, Hamas’s October 7 attacks came as a complete shock, especially when compared to the months of American intelligence warnings that preceded Russia’s full-scale invasion of Ukraine in 2022. US intelligence capabilities were primed to spot conventional indicators such as Russian staging of tanks, repositioning of aircraft, and assembly of uniformed troops. But they were not prepared to detect Hamas’s underground assembly of rockets, drones, and small vehicles. Israel itself was caught completely off guard because of the unconventional character of Hamas’s preparations. Prior to October 7, Israeli leadership was convinced that the West Bank posed a much larger security threat compared to Hamas in Gaza. For several years, Hamas’s attacks against Israel were limited to rocket barrages. Israel’s potent air defense network intercepted over 90 percent of all incoming projectiles, resulting in limited damage to Israeli infrastructure. This led Israeli leadership to believe that the situation in Gaza was relatively contained and manageable, prompting the government to shift the bulk of its military forces to contain the West Bank. This shift left the Gaza front critically underdefended. Hamas exploited this imbalance, seizing the opportunity for its devastating strike. Israel’s assumption of manageable risk proved to be a critical miscalculation, underscoring how quickly perceived stability can unravel when facing unconventional threats.

For US forces, this raises critical questions about how much military presence is needed to deter the wider axis of resistance. This is especially important as the United States negotiates a series of diplomatic agreements within the region. These agreements are broadly meant to reduce US miliary presence in exchange for peace with key regional stakeholders. They include the withdrawal of troops in Iraq, achieving a lasting peace in Yemen, and the future of Iran’s nuclear program. But failure to achieve diplomatic breakthroughs could increase the probability of surprise attacks on US interests within the region. In Iraq, Iranian-backed militias could rapidly assemble forces to threaten, for example, the US embassy in Baghdad. This would be a severe blow to US regional presence and diplomatic influence. In Yemen, the Houthis could resume targeting Saudi oil facilities, Emirati airports, and international shipping, which directly affects the price of energy. In Iran, failure to achieve a lasting nuclear deal could push Tehran’s leadership to develop nuclear weapons, irrevocably undermining regional stability. Iran’s recent surprise strike against Israel demonstrates the potential devastation of future ballistic missile attacks.

While it is impossible to precisely forecast the next Middle East conflict, it is almost certain that it will be harder to foresee its opening compared to the threats emanating from China or Russia. Iran’s axis of resistance presents a unique threat dynamic distinguished by sudden escalations and irregular warfare. This makes it essential for the US military to remain flexible and prepared for the unexpected, lest it face the same strategic surprises that have haunted Israel.

Tunnel Warfare: The Ultimate Equalizer

The second major lesson of the Gaza conflict centers on the importance of tunnel warfare for outgunned nonstate actors. By dispersing its forces underground and using tunnels to move around the battlefield, Hamas has prolonged its resistance against Israel’s superior firepower. Its tunnel network enables Hamas to withstand Israeli offensives, but crucially it has also forced Israeli forces to clear and reclear the same areas multiple times particularly in northern Gaza neighborhoods like Jabaliya and Zeitoun. As a result, international confidence in Israel’s ability to permanently destroy Hamas has eroded, with many questioning the long-term effectiveness of Israel’s military campaign. The tunnels have allowed Hamas not only to survive but to impose significant economic, military, and social costs on Israel. For example, Hamas’s survival in prolonged conflict has led to the Israeli Supreme Court ending the draft exemption for ultra-Orthodox Jewish students. This is a significant shift in the social contract between Israel and its citizens, illustrating the effectiveness of Hamas’s underground warfare in achieving both military and political goals.

For the United States, Hamas’s success with tunnel warfare presents a critical lesson, particularly when considering future conflicts that could pit the United States, even indirectly in support of allies and partners, against Iran and its axis of resistance. These militia networks are likely studying Hamas’s tactics and are expected to further invest in their own tunnel networks. Hezbollah and the Houthis, for example, benefit from mountainous terrain that naturally conceals and protects their underground infrastructure, making them even more difficult to neutralize—terrain Hezbollah has leveraged by building up its own network of tunnels across southern Lebanon. Given the likely spread of tunnel warfare across the region, the US military must closely study Hamas’s use of tunnels to develop tactics for defeating or mitigating this form of defense.

When considering offensive operations, the US Army should study how Israel has determined which underground fortifications can be bypassed, isolated, or neutralized to conserve munitions and maintain momentum. For defensive operations, the Army should study how Hamas has effectively fought both below and above ground. It might not seem intuitive why US forces would ever fight like Hamas, few would argue that US forces will never fight in dispersed small teams against a superior (at least situationally) force—precisely what Hamas has done over the past year. We would be wise to analyze successful operational approaches wherever lessons can be learned.

Sustainment While Besieged

Hamas has adopted a highly adaptable and effective sustainment strategy despite being besieged by land, air, and sea. This not only underscores the group’s resilience but also signals potential future sustainment strategies that Iran’s axis of resistance could adopt in other conflicts in the region. Two key sustainment efforts stand out, helping to explain why Hamas has been able to continue military operations, albeit at a reduced paced. These include Hamas’s ammunition acquisition and fighter recruitment operations.

Hamas’s ammunition acquisition can be broken down into two main components. First, it remanufactures unexploded Israeli bombs, missiles, and artillery shells into its own armor-piercing, shoulder-fired rockets, indirect-fire missiles, and roadside improvised explosive devices. Hamas engineers have established substantial underground factories for this purpose, allowing them to turn Israeli munitions failures into a strategic advantage. As Ghazi Hamad, a member of Hamas’s political bureau, explained, “We succeeded in making manufacturing factories underground because we knew that one day all the channels would be closed.” This proactive approach has ensured a continuous supply of munitions despite the blockade. One Israeli intelligence officer estimated that as much as 10–15 percent of Israeli munitions launched at Gaza fail to detonate upon impact. This foresight allowed Hamas to create a reliable supply chain for munitions. Some of these allegedly include the Korean War–era M117 bomb, which at 750 pounds contains enough explosives to use on a substantial number of Hamas rockets and missiles. With some estimates suggesting that Israel has dropped over seventy thousand tons of explosives as of April, even a dud rate far below the lowest estimates still gives Hamas, if all unexploded ordnance is secured and used, millions of pounds of explosives to remanufacture. As one Hamas commander emphasized, “Our strategy aimed to repurpose these [dud munitions], turning this crisis into an opportunity.” This resourcefulness is why some analysts suggest Hamas is not concerned about running out of explosives and munitions—the group has likely acquired a lifetime supply.

In addition to repurposing unexploded ordnance, Hamas has also relied on battlefield scavenging to replenish its arsenal. After clashes with Israeli forces, Hamas fighters systematically comb through the battlefields to collect leftover ammunition, small arms, and other military equipment. This practice has allowed the organization to quickly resupply its forces with weapons that are often left behind by withdrawing Israeli troops, further bolstering its capacity to sustain prolonged military engagements. While not nearly as sophisticated as remanufacturing Israeli unexploded bombs, this technique is simple and likely good enough to continue fighting in small-scale ambushes for the foreseeable future.

Recruiting fighters is the second key element of Hamas’s battlefield sustainment. While precise figures are difficult to determine, Hamas’s spokesperson has previously claimed that it has recruited “thousands” of new fighters over the past year, with thousands more waiting to join. Recently senior Hamas official Osama Hamdan stated in an Agence France-Press interview, “The number of casualties . . . is much less than what is expected in a battle of this size, level and breadth.” And those casualties, he claimed, were offset. “There were martyrs and there were sacrifices,” he acknowledged, “but in return, there was an accumulation of experiences and the recruitment of new generations into the resistance.” While the veracity of these claims may be disputed, they indicate a strong level of confidence in Hamas leaders’ ability to absorb losses and recruit new fighters. Were they not confident, they likely would have made significant political concessions to achieve a ceasefire. Understanding the nuances of how Hamas recruits fighters, even under extraordinarily difficult conditions, will shed light on how other nonstate actors will regenerate their forces in future conflict. Such an understanding is crucial for the United States to develop effective counterstrategies that require less force to achieve American political objectives.

“I say clearly: no matter the sacrifices, consequences, or future possibilities, the resistance in Lebanon will not stop supporting Gaza.”

These were among the final words of Hassan Nasrallah, the late secretary-general of Hezbollah. His speech not only echoed the sentiments of the Lebanese resistance but also reflected the broader unity of the axis of resistance across what Israeli Prime Minister Benjamin Netanyahu describes as seven fronts, where Iran and its proxies are perhaps more committed to the defense of the Palestinian cause now, one year after October 7, than ever before. Each is actively studying the lessons learned throughout the past year, as must we. Few could have predicted the shock of that day, or the intensity of the Israeli response after. Fewer still could have predicted the pager explosions, Nasrallah’s sudden demise, and Iran’s subsequent missile strike. This is why, first and foremost, the Gaza conflict has underscored the strategic unpredictability and explosive volatility of Middle Eastern conflicts. But the shocking elements above ground were only half the story. With little comparison, it’s been one of the most intensive years of underground combat that mankind has seen, revealing the incredible effectiveness of tunnel warfare for defending forces. Perhaps even more incredible, however, is the herculean effort Hamas has undertaken to sustain its ammunition intake and regenerate its forces while completely besieged. Looking forward, it is essential for the US military to accept these insights—and where appropriate, adapt based on them. Millions of lives, the free flow of energy, and America’s global military and diplomatic posture hang in the balance. Ultimately, the lessons learned from Gaza are not only vital for Israel but for the United States and its broader strategic interests in the Middle East and the world beyond.

Major Harrison Morgan is a US Army foreign area officer and a former MWI nonresident fellow.

The views expressed are those of the author and do not reflect the official position of the United States Military Academy, Department of the Army, or Department of Defense.

Image credit: IDF Spokesperson’s Unit