For more than a decade, Saudi Arabia has confronted an adversary it has been unable to defeat decisively. The kingdom possesses one of the world’s most powerful military establishments, operates sophisticated American and European aircraft, and spends tens of billions of dollars annually on defense. Yet the Houthis, an armed movement that emerged from the mountains of northern Yemen, have survived years of bombardment, maintained control over substantial territory, and repeatedly demonstrated their ability to threaten countries far more powerful than themselves.

According to the 2026 Global Firepower ranking, Saudi Arabia possesses the world’s 25th most powerful military. The Stockholm International Peace Research Institute (SIPRI) estimates that the kingdom spent $83.2 billion on defense in 2025, making it the world’s eighth-largest military spender. The disparity between Saudi military resources and those available to the Houthis is enormous. Nevertheless, the Saudi-led intervention that began in March 2015 failed to achieve its central objective of restoring the internationally recognized Yemeni government to power in Sanaa.

The United States encountered a similar strategic dilemma. In March 2025, President Donald Trump ordered an intensive military campaign against Houthi positions in Yemen. American aircraft struck military facilities, weapons depots, radar installations, and other targets associated with the movement’s ability to threaten international shipping. Washington possessed overwhelming technological superiority, yet the campaign ended in May with a limited agreement under which the Houthis would stop attacking American vessels. The arrangement did not extend to Israel, and the movement remained capable of threatening regional security.

The problem extends well beyond Yemen’s borders. The Houthis occupy a strategically important position overlooking the southern approaches to the Red Sea, near the Bab el-Mandeb Strait, one of the world’s most consequential maritime chokepoints. The Houthis occupy a strategically important position overlooking the southern approaches to the Red Sea, near the Bab el-Mandeb Strait, one of the world’s most consequential maritime chokepoints. Through this narrow passage, vessels connect the Indian Ocean with the Red Sea and, ultimately, the Suez Canal. The Houthis do not need to physically occupy or completely close the strait to disrupt international commerce. The credible threat of missile or drone attacks can be enough to force shipping companies to reroute vessels around Africa, increasing transportation costs, insurance premiums, and delivery times.

For Saudi Arabia, the threat is more immediate. Its energy infrastructure, airports, commercial facilities, and population centers have repeatedly been exposed to attacks originating from Yemen. For Israel, the Houthis represent another hostile actor capable of projecting missiles and drones across considerable distances. For the United States, they illustrate how a comparatively small military organization can impose disproportionate economic and operational costs on a superpower.

Why, then, are the Houthis so difficult to defeat?

The difficulty is closely related to the sheer extent of the territory the Houthis control and its rugged terrain. Unlike Hamas, whose principal territorial stronghold is confined to the approximately 365 square kilometers of the Gaza Strip, the Houthis control extensive regions of northern and western Yemen, encompassing mountain ranges, deep valleys, remote rural areas, and major population centers, including Sanaa, the country’s capital, as well as Hodeidah, Saada, Dhamar, and Amran.

Hamas developed an extensive network of underground tunnels beneath one of the most densely populated territories in the world, complicating Israeli military operations. The Houthis, however, benefit from a vastly larger and more geographically complex environment, which provides opportunities for dispersal, concealment, and reorganization.

Unlike Gaza, Yemen cannot be isolated through a relatively small number of border crossings. Its geography offers numerous opportunities for dispersal, concealment, and reorganization. The Houthis also possess political institutions, local networks, and military structures that have allowed the movement to maintain territorial control and continue operating despite years of sustained military pressure.

Even an extensive conventional bombing campaign can degrade their capabilities without eliminating their ability to continue fighting.

This raises an uncomfortable question that deserves examination, not because it constitutes a recommendation, but because it tests the ultimate limits of military power.

Could a tactical nuclear strike break the Houthis?

Before considering the strategic implications, it is necessary to distinguish tactical nuclear weapons from strategic nuclear weapons. The distinction is based primarily on their intended military role rather than an absolute threshold of explosive yield. Tactical nuclear weapons are generally associated with battlefield or theater-level military objectives, although their political consequences can be profoundly strategic.

Nuclear weapons can have yields substantially below those of the atomic bombs dropped on Japan in 1945. A weapon with a yield of one kiloton releases energy equivalent to approximately one thousand tons of TNT. Hiroshima’s atomic bomb had an estimated yield of 15 kilotons, while the weapon detonated over Nagasaki produced approximately 21 kilotons.

Interestingly, the more powerful bomb caused fewer deaths.

Approximately 140,000 people died in Hiroshima by the end of 1945, compared with an estimated 70,000 in Nagasaki. These figures are necessarily approximate, and several factors explain the difference, including population distribution, the location of the explosions, urban construction, and geography. Nagasaki’s surrounding hills and valleys influenced the distribution of blast damage, while Hiroshima’s relatively open terrain contributed to more widespread destruction.

The comparison illustrates an important physical principle: explosive yield alone does not determine the consequences of a nuclear detonation.

Yemen’s mountainous geography introduces an additional complication. Terrain can obstruct some blast effects while concentrating others, making damage patterns highly dependent on local conditions. More importantly, a nuclear explosion, regardless of its yield, would affect only a limited geographical area relative to the enormous territory in which the Houthis operate.

A limited nuclear strike could not reasonably be expected to physically eliminate an organization dispersed across such an extensive landscape. Even the destruction of important military facilities would not guarantee the disappearance of its leadership, political institutions, ideological foundations, or capacity to reorganize.

The comparison with Hiroshima and Nagasaki also has limitations. Those were attacks against populated cities during a world war, not against dispersed insurgent forces in mountainous terrain. Their humanitarian consequences cannot be treated as a predictive model for Yemen.

Nevertheless, the underlying strategic question remains.

If a tactical nuclear strike could not guarantee the physical destruction of the Houthis, what would be its purpose?

The most plausible argument would concern coercion rather than annihilation: an attempt to inflict such an extraordinary psychological shock that the movement’s leadership would reconsider the costs of continuing its attacks.

But this assumption immediately encounters another difficulty. There is no guarantee that the Houthis would respond as their adversaries intended.

The movement has endured years of warfare, severe military losses, and repeated attacks against its infrastructure. Its leaders have demonstrated a willingness to absorb considerable punishment while preserving their political objectives. A nuclear strike might frighten them into changing course. It might also strengthen their ideological narrative, encourage retaliation, or convince them that continued resistance was necessary.

Military destruction and political submission are not synonymous.

History provides several revealing precedents.

In 1954, as French forces faced defeat at Dien Bien Phu in Indochina, American officials discussed military intervention, including proposals involving tactical atomic weapons. A declassified memorandum dated April 7, 1954, confirms that Pentagon planners examined whether three tactical atomic weapons could defeat Viet Minh forces around the besieged French position. President Dwight Eisenhower did not authorize a nuclear attack.

Fourteen years later, during the 1968 siege of Khe Sanh in Vietnam, American military planners examined nuclear contingency options under Operation Fracture Jaw. Declassified State Department records confirm that President Lyndon Johnson ordered the termination of nuclear contingency planning on February 11, 1968.

Neither historical episode is identical to Yemen. The Viet Minh and North Vietnamese forces operated under different political, military, and international conditions. Nevertheless, both demonstrate that the possibility of using tactical nuclear weapons in a conventional conflict has been considered before, and that American presidents ultimately declined to authorize their employment.

The political problem today would be even more extraordinary.

Since the destruction of Nagasaki on August 9, 1945, no nuclear weapon has been used in warfare. More than eight decades have passed without another combat nuclear detonation. That restraint has become one of the most consequential norms in international security.

Who would be willing to break it over Yemen?

Saudi Arabia does not possess a declared nuclear arsenal. The United States does, but any American administration contemplating nuclear use against a non-nuclear armed movement would face immense legal, humanitarian, diplomatic, and strategic consequences. Israel is widely believed to possess nuclear weapons, although it maintains a longstanding policy of nuclear ambiguity. An Israeli nuclear strike would therefore have implications extending far beyond the immediate conflict with the Houthis.

Even the hypothetical selection of a remote, sparsely populated military location would not eliminate these problems. A tactical nuclear weapon is not inherently discriminate simply because it has a relatively low yield or is intended for battlefield use. Radioactive contamination, civilian exposure, environmental consequences, and the possibility of escalation would remain serious concerns. The International Committee of the Red Cross considers it extremely doubtful that nuclear weapons could ever be used in accordance with international humanitarian law, including in remote areas.

The question is whether any conceivable military advantage could justify crossing a threshold that successive American presidents refused to cross even during major wars.

And there is another paradox.

The extraordinary consequences of nuclear use may make a nuclear threat less credible, rather than more effective. Houthi leaders could calculate that neither Washington nor Jerusalem would accept the international repercussions of employing such a weapon. In that case, the threat might fail to produce the desired psychological effect.

Conversely, if the weapon were actually used, its political consequences would already have occurred, regardless of whether the Houthis subsequently changed their behavior.

The distinction between deterrence and compellence is essential here. Deterrence seeks to prevent an adversary from undertaking an action. Compellence seeks to force an adversary to stop or reverse behavior already underway. If the objective were to end ongoing Houthi attacks, the central problem would be coercion, not simply deterrence.

And coercion is notoriously difficult when the adversary is willing to endure punishment.

The Houthis do not need to defeat the United States, Israel, or Saudi Arabia in a conventional war. They need only preserve enough organizational capacity to continue imposing costs and demonstrating that they have not surrendered. Their strategic definition of success can therefore be dramatically different from that of their opponents.

A nuclear strike might destroy military assets. It might produce an unprecedented psychological shock. But whether it could break the movement’s determination to continue fighting is fundamentally unknowable.

What is considerably more predictable is the cost of crossing the nuclear threshold.

The first nuclear attack since 1945 would establish a precedent with implications extending far beyond Yemen. It could weaken the restraint surrounding nuclear weapons, intensify regional instability, and encourage other nuclear-armed states to reconsider the circumstances under which they might employ their own arsenals.

The ultimate irony is that a tactical nuclear strike intended to demonstrate overwhelming power could instead expose the limitations of that power.

Saudi Arabia has already demonstrated that military superiority does not guarantee victory against the Houthis. The United States has demonstrated that an intensive bombing campaign can produce a limited agreement without eliminating the underlying threat. Yemen’s geography makes the complete physical destruction of the movement through a limited attack an unrealistic expectation.

A nuclear weapon would change the magnitude of destruction. It would not necessarily change the political equation.

And if the only plausible strategic purpose of crossing the nuclear threshold were to break the Houthis psychologically, the world would be accepting extraordinary and potentially irreversible consequences for an outcome that no one could guarantee.

That may be the most important lesson of this entire exercise: the possession of overwhelming destructive power does not mean that every adversary can be compelled to surrender.

Not even with a nuclear weapon.

However, no analysis can predict the political decisions of any leader in the world, especially under extreme circumstances. The most improbable option can become the chosen one when leaders face perceived existential threats, domestic pressure, miscalculation, or the belief that restraint itself has become more dangerous than escalation.