Defensive Realism, Regional Power Competition, and the Escalation of Houthi Threats in the Red Sea
Written by Dhyana Holla; Edited by Alex Tapia
April 19, 2026
Abstract
Houthi Attack on the Red Sea
Source: Transnational Matters
The escalation of Houthi attacks against commercial shipping and naval vessels in the Red Sea has transformed what for years appeared to be a largely domestic conflict into a prominent global crisis, threatening the international balance of power. Following the outbreak of the Israel-Hamas war, the Houthis have carried out a series of missile strikes, drone attacks, and attempted hijackings that have reshaped and endangered maritime security in the Red Sea. These actions have forced shipping companies to reroute commercial vessels from the Red Sea to the Cape of Good Hope, adding approximately 3,500 nautical miles and nearly $1 billion in additional transportation costs to global supply chains. The economic repercussions of such disruptions have compounded existing inflationary pressures and highlighted the vulnerability of the international system to non-state actors capable of exploiting weaknesses in global trade.
Amid these escalating tensions, the United States has adopted a multifaceted approach aimed at protecting freedom of navigation, supporting regional partners, and maintaining a stable international order. Washington’s priorities have historically revolved around the importance of maintaining freedom of trade and navigation, centralizing around the economic gains the United States faces with the continuation of global trade and the economic stability that this freedom declares. Yet Washington’s response remains constrained by the risk of broader conflict with Iran, the fragility of political conditions within Yemen, and the emergence of Russia and China as diplomatic supporters to the current Houthi dominance. These tensions reveal the complexities of modern power politics, where state and non-state actors simultaneously cooperate and contrastingly undermine each other’s strategies.
This research paper argues that defensive realism provides the most analytically sound framework for explaining the rise of the Houthi threat and the strategic environment shaping U.S. policy options. Rooted in the logic of the international system, defensive realism maintains that states, faced with anarchy and uncertainty in the absence of global authority, pursue strategies aimed primarily at securing survival rather than maximizing power. When applied to Yemen and the broader Middle East, defensive realism helps clarify how insecurity, power vacuums, and threat perception generate behaviors that appear aggressive but are fundamentally defensive in nature. This paper further argues that the Houthis’ emergence as a regional actor, Iran’s strategic support, Saudi Arabia’s patterns of intervention, and the ambivalent positioning of Russia and China all reflect the dynamics predicted by defensive realism and poses threats to the United States’ controversial stance as a hegemonic power in today’s international order.
Historical Origins of the Conflict and the Houthi Rise to Power
Understanding the present Red Sea crisis requires tracing the origins of the Houthi movement within Yemen’s political transformation. The Houthis, formally known as Ansar Allah, emerged initially as a revivalist Zaydi Shia movement in the 1990s. Their early grievances centered on the marginalization of Zaydi communities, opposition to perceived Saudi-influenced Wahhabi encroachment, and resentment toward the authoritarianism of President Ali Abdullah Saleh’s government.
Yet it was the 2011 Arab Spring uprising, which fractured Yemen’s already weak state institutions, that created the structural opportunity for the Houthis to expand from an insurgency into a national political force. When Saleh was ousted and his successor, Abd-Rabbu Mansour Hadi, proved unable to consolidate power, Yemen’s governance structures rapidly deteriorated. The power vacuum that existed allowed the Houthi extremist group to quickly take power as the dominant political actor that continued to exploit past Yemeni state structure weakness through civil neglect, allowing them to maintain some sort of legitimacy.
The National Dialogue Conference launched in 2012 was intended to build a new political framework for the country, but the process failed to address the Houthis’ core security and representation concerns. By 2014, as state capacity continued to unravel, the Houthis capitalized on political disarray and public discontent to advance southward, ultimately seizing the capital, Sana’a. In doing so, they filled the power vacuum left by the disintegrating Yemeni state, consistent with the predictions of defensive realism regarding actor behavior in anarchic or collapsing political environments.
The 2015 Saudi-led intervention dramatically internationalized the conflict. Saudi Arabia framed the Houthi ascendancy as an extension of Iranian influence and thus a direct threat to its national security. From Riyadh’s perspective, allowing a perceived Iranian-aligned group to control Yemen—situated along critical maritime routes and bordering the kingdom—posed unacceptable strategic risks. Saudi-led airstrikes, combined with blockades and economic pressure, aimed to quickly reverse Houthi gains. Instead, they entrenched the group further, allowing it to mobilize nationalist sentiment by portraying itself as the defender of Yemen against foreign aggression.
The intervention also deepened Houthi reliance on Iran. While the relationship between Tehran and the Houthis is often overstated, Iranian support grew substantially in response to the Saudi campaign. Iran provided missile technology, drone systems, tactical training, and financial support, enabling the Houthis to build an increasingly sophisticated arsenal. Yet the relationship remained asymmetric and transactional rather than forceful. The Houthis maintained significant autonomy, reflecting a mutual alignment of interests rather than control.
By 2020, the Houthis had solidified their rule over northern Yemen, including key population centers, ports, and government institutions. The collapse of the Yemeni state, prolonged conflict, and external intervention had created the structural conditions in which a non-state actor could not only survive but challenge regional powers and influence global trade routes.
Defensive Realism as the Theoretical Lens
A trade ship in the Red Sea
Source: Transnational Matters
Defensive realism, grounded in the structural logic of neorealism, offers a powerful framework for understanding the escalation of the Houthi threat and the strategic behaviors of regional and global actors. According to defensive realists such as Kenneth Waltz and Stephen Walt, states primarily seek security and survival rather than dominating others. Overly aggressive expansion is discouraged because it provokes balancing coalitions, increases vulnerability, and ultimately undermines long-term security. In this perspective, the international system incentivizes restraint and caution, while power accumulation is pursued only to the extent necessary to ensure safety.
This theoretical lens explains the behavior of the Houthis not as ideological adventurism or offensive expansionism, but as a series of rational responses to threats and structural vulnerabilities. From the early clashes with the Yemeni government to the present maritime confrontations, the Houthis have consistently framed their actions as defensive measures against foreign intervention, political exclusion, and perceived existential threats. Defensive realism helps clarify why the Houthis seized Sana’a when the opportunity arose, consolidated military capabilities, and continued to leverage asymmetric strategies to deter superior adversaries. Their maritime attacks, while appearing offensive on the surface, serve a strategic logic: increasing their bargaining power, deterring external intervention, and signaling that any military action against them will impose high costs.
Iran’s behavior aligns even more clearly with defensive realist predictions. Tehran’s support for the Houthis is often interpreted through the lens of regional hegemony or ideological expansion. Yet defensive realism suggests a simpler explanation: Iran seeks to prevent encirclement by U.S. and Saudi influence, reduce the threat posed by rival Sunni powers, and extend its defensive buffer zones through cost-effective proxy relationships. Supporting the Houthis enhances Iran’s deterrence without exposing it to direct military confrontation. Crucially, Iran has demonstrated a consistent preference for calibrated escalation rather than full-scale conflict, underscoring its fundamentally defensive strategic posture.
The United States, too, behaves in ways consistent with defensive realism. Although Washington possesses overwhelming military capabilities, it has avoided maximalist strategies in Yemen due to the risks of escalation with Iran, entanglement in an intractable civil war, and the political costs of deepening involvement in another Middle Eastern conflict. U.S. decision-making has been shaped by the desire to maintain regional stability, protect global trade routes, and prevent the emergence of balancing coalitions. The strategic restraint demonstrated by the United States—despite repeated Houthi provocations—reflects the structural incentives emphasized by defensive realists.
Complex Interactions Among Regional and Global Actors
The Yemen conflict cannot be understood solely through the actions of the Houthis, Iran, or the United States. The involvement of Saudi Arabia, the United Arab Emirates, Russia, and China has created a multilayered geopolitical environment that reflects broader patterns of global competition. Defensive realism illuminates how these actors navigate insecurity, shifting alignments, and the risks of overextension.
Saudi Arabia’s intervention in Yemen was driven by acute security fears rather than revisionist ambitions. Riyadh perceived the Houthi takeover—and their ties to Iran—as a direct encroachment on its sphere of influence. Defensive realism predicts that states will respond forcefully when they believe their survival is at stake, particularly when threats emerge on their borders. Yet Saudi Arabia’s prolonged involvement produced diminishing returns, encouraged retaliation from Iran, and contributed to regional instability. Recognizing this, Riyadh has increasingly sought political settlement rather than military victory, aligning with the defensive realist expectation that states eventually recalibrate strategies to reduce insecurity.
Russia and China’s roles reveal an additional layer of competition shaped by the international system. Both countries have engaged diplomatically with the Houthis, abstained from UN resolutions condemning them, and criticized U.S. military actions. Russia, driven by geopolitical rivalry with the United States, seeks to expand its influence in the Middle East and portray itself as a defender of actors resisting Western pressure. China’s motives are primarily economic: ensuring the stability of trade routes essential to its global supply chains. Yet both states share an interest in constraining U.S. influence, and their cautious support for the Houthis reflects a balancing strategy consistent with defensive realism. Their actions widen the strategic costs for the United States, reinforcing the need for restraint and multilateral coordination.
The persistence of conflict in Yemen stems from structural insecurity, regional rivalries, and the absence of credible political institutions. The Houthis’ consolidation of power is driven by a desire for self-preservation in a fragmented state. Iran supports them as part of a broader defensive strategy to deter rivals. Saudi Arabia seeks to prevent encirclement and protect its territory. Russia and China maneuver to weaken U.S. influence while advancing their own strategic interests. Cooperation remains limited because each actor views concessions as potential threats to security. The United States’ attempts to build a maritime coalition to protect Red Sea shipping faced hesitation from Saudi Arabia, Egypt, and other regional partners who feared being drawn into escalatory dynamics. Even shared interests—such as protecting freedom of navigation—are overshadowed by divergent threat perceptions and geopolitical mistrust. Defensive realism explains why durable cooperation is difficult: actors are reluctant to align fully when doing so might compromise their autonomy or entangle them in conflicts they cannot control. The absence of trust and the persistence of security dilemmas make comprehensive regional cooperation unlikely without substantial structural change.
Conclusion
The Red Sea crisis illustrates the enduring relevance of defensive realism in making sense of complex regional and global conflicts. The Houthis’ rise, Iran’s calibrated support, Saudi Arabia’s intervention, and the involvement of Russia and China all reflect strategic behaviors grounded in the pursuit of security rather than expansion. The United States, facing multiple constraints and risks of escalation, must navigate an international environment shaped by insecurity, fragmentation, and great-power competition.
Defensive realism offers both analytical clarity and practical guidance. It suggests that U.S. strategies focused on stabilizing the region, avoiding overreaction, pursuing multilateral diplomacy, and addressing the underlying political conditions in Yemen will be more effective than maximalist military approaches. As the international system continues to evolve, the Red Sea crisis stands as a reminder that in an anarchic world, insecurity—rather than ambition—remains the primary driver of state and non-state behavior.
